Advertisement: Attention pond owners! Ninety-eight percent of mosquito

(A) The most effective way to control the numbers of mosquitoes in a given area is to destroy the mosquito larvae in that area. -->incorrect --> argument talks about killing mosquitoes without affecting other species and negating this statement doesn't make any sense
(B) Populations of mosquitoes are not dependent on a single body of water within an area as a place foe their larvae to hatch and develop
(C) There are no insect pests besides mosquitoes that pond owners might want to eliminate from in and around their pond.
(D) The effectiveness of BTI in destroying mosquito larvae In a pond does not require the pond owner’s strict adherence to specific application procedures.
(E) The fish, frogs, and beneficial insects in and around a pond-owner’s pond do not depend on mosquito larvae as an important source of food ---> Correct --> if fish frogs and other beneficial insects depends on the larvae, then destroying the larvae will impact these.

Option A is not an assumption here. It can be the MOST effective way to destroy mosquitoes or the LEAST effective way or just a GOOD way. Argument does not depend on this.

An assumption is a must be true option to hold the conclusion true. The most effective way to control the numbers of mosquitoes in a given area is to destroy the mosquito larvae in that area. To destroy mosquito larvae it need not to be the most effective. There might be other effective ways but we are not concerned with those. They are out of scope. If the current plane is effective then it is enough for us.

So, see that it is not a must be true and hence not an assumption.

we need to find an answer that would connect two pieces: 1) Bti destroyes mosquitto 2) fish stays alive
E does the job, because of the wish to be dependent of mosquitos->then BTI would affect fish as well

Advertisement: Attention pond owners! Ninety-eight percent of mosquito larvae in a pond die within minutes after the pond has been treated with BTI. Yet BTI is not toxic to fish, birds, animals, plants, or beneficial insects. So by using BTI regularly to destroy their larvae, you can greatly reduce populations of pesky mosquitoes that hatch in your pond, and you can do so without diminishing the populations of fish,frogs, or beneficial insects in and around the pond.

Which one of the following is an assumption on which the argument depends?

Assumption question ask to identify the link between the premise and the conclusion. here the premise is that the BTi kills mosquito larvae and the conclusion is that the BTi should be used to kill all the larvae in the pond.The assumption is that the peope do want to kill the larvae and it does not impact anything.

Negation Test. Hyposthis an opposite statement of the sorted statement and if it breaks the argument then it is the correct answer. for asuumption question.

(A) The most effective way to control the numbers of mosquitoes in a given area is to destroy the mosquito larvae in that area. The efferctivness is not the subject of the argument
(B) Populations of mosquitoes are not dependent on a single body of water within an area as a place foe their larvae to hatch and develop as the argument suggest that all the water bodies should be treated with BTI
(C) There are no insect pests besides mosquitoes that pond owners might want to eliminate from in and around their pond.Other insects are out of scope.
(D) The effectiveness of BTI in destroying mosquito larvae In a pond does not require the pond owner’s strict adherence to specific application procedures. out of scope for the assumption type question
(E) The fish, frogs, and beneficial insects in and around a pond-owner’s pond do not depend on mosquito larvae as an important source of food.Correct answer and passes the negation test.

Here is the argument core:

BTI kills mosquito larvae.
BTI doesn't kill other species.
Therefore by using BTI, you can kill mosquito larvae without affecting/killing other species.

The assumption gap is clearly one that is needed to bridge the link between the larvae and other species. If there is a way for mosquito larvae to impact other species, then that would be a problem to the argument. Hence, E.  

The conclusion of the argument is that the population of mosquitoes can be greatly reduced using method X without damaging the population of fish, frogs, or some good insects.

The correct answer must address the "without damaging" part. Otherwise, the whole argument will fall apart.

Option A only talks about the effectiveness of method X. It does not touch on the main point of the conclusion, i.e. will other species be affected if method X is used to kill mosquitoes?

So, option E is by far the best option.

Advertisement: Attention pond owners! Ninety-eight percent of mosquito larvae in a pond die within minutes after the pond has been treated with BTI. Yet BTI is not toxic to fish, birds, animals, plants, or beneficial insects. So by using BTI regularly to destroy their larvae, you can greatly reduce populations of pesky mosquitoes that hatch in your pond, and you can do so without diminishing the populations of fish,frogs, or beneficial insects in and around the pond.

Which one of the following is an assumption on which the argument depends?

I like E

(A) The most effective way to control the numbers of mosquitoes in a given area is to destroy the mosquito larvae in that area.
This is irrelevant. It may be the most effective way but there is no underlying assumption saying so

(B) Populations of mosquitoes are not dependent on a single body of water within an area as a place foe their larvae to hatch and develop
I almost picked this one. If mosquitos are not dependent on one body of water it would make sense that using BTI would help get rid of them at individual owners pond. I kept this as a candidate

(C) There are no insect pests besides mosquitoes that pond owners might want to eliminate from in and around their pond.
Irrelevant

(D) The effectiveness of BTI in destroying mosquito larvae In a pond does not require the pond owner’s strict adherence to specific application procedures.
Irrelevant

(E) The fish, frogs, and beneficial insects in and around a pond-owner’s pond do not depend on mosquito larvae as an important source of food.
I chose this over B because because if the fish and frogs are not dependent on the larvae for food they would stay at the pond even if the larvae population were reduced, but if they were dependent they would leave the pond with the reduction in larvae

That's because if you look at the conclusion it has two parts:
1. That mosquito larvae can be destroyed
2. The larvae can be destroyed without affecting fishes and other living things in the pond.

A only takes care of 1. E takes care of 2. E effectively says that if fishes depended on larvae for food, they would die once the larvae are gone.

I concluded that using BTI will destroy larvae and reduce the mosquito population greatly.

so negating the conclusion: In what scenario can BTI does not destroy the larvae and does not reduce the population greatly,

Infering : I choose option D .

Why did I concluded wrong?

­the ultimate goal is doing without diminishing the populations of fish,frogs, or beneficial insects in and around the pond so E is the correct answer because if  the fish, frogs, and beneficial insects depend on mosquito larvae as an important source of food  thenn, killing larve will kill the fish, frogs, and beneficial insects as well

­Here's the exact conclusion:

So by using BTI regularly to destroy their larvae, you can greatly reduce populations of pesky mosquitoes that hatch in your pond, and you can do so without diminishing the populations of fish,frogs, or beneficial insects in and around the pond.

So, the conclusion is about what "you can" do.

Now, let's consider (D).

(D) The effectiveness of BTI in destroying mosquito larvae In a pond does not require the pond owner’s strict adherence to specific application procedures.

Notice that, if even if the effectiveness of BTI in destroying mosquito larvae In a pond DOES require the pond owner’s strict adherence to specific application procedures, it is still the case that, by adhering to those procedures, "you can" destroy mosquito larvae in a pond.

So, we don't need to assume (D) to arrive at the argument's conclusion.­