Because of recent seismic activity all along the Bleisner

Hey
Thanx people. Got the subject point. I had chosen "C". Consider the below two cases

1. environmental groups are concerned that offshore oil drilling and mineral exploration taking place

2. environmental groups are concerned that offshore oil drilling and mineral exploring taking place

I mean why is oil drilling and mineral exploration better than offshore oil drilling and mineral exploring for parallelism.
This is what was explained in OE.
Apologize if it seems very basic.

the first part of the sentence modifies the subject Environmental group.Hence options A,B and E prevail.
E mineral exploring --- wrong usage of participle form.
A concern has to be described hence usage of by is not correct.

hence B prevails.

i pick B. the intended meaning is clear only in option B. other choices are just convoluted

Correct answer = B

A) environmental groups are concerned by offshore oil drilling and mineral exploration taking place --> "concerned by" vs "concerned that" = second is better

B) environmental groups are concerned that offshore oil drilling and mineral exploration taking place --> Correct

C) a concern by environmental groups is that the offshore oil drilling and mineral exploring taking place --> "because"...."a concern" = doesn't make sense (eliminate)

D) a concern of the environmental groups is the offshore oil drilling and mineral exploring taking place --> (eliminated for the same reason as C)

E) environmental groups are concerned by the offshore oil drilling and mineral exploring taking place --> same as explanation for A

1. "environmental groups" vs "a concern"
C) a concern by environmental groups is that the offshore oil drilling and mineral exploring taking place
D) a concern of the environmental groups is the offshore oil drilling and mineral exploring taking place

Because ... , is a subordinator modifying the action (Why are they concerned? Because of ...)
The action should be done by "environmental groups," not "a concern"

2. "concerned by" vs "concerned that"
A) environmental groups are concerned by offshore oil drilling and mineral exploration taking place
B) environmental groups are concerned that offshore oil drilling and mineral exploration taking place
E) environmental groups are concerned by the offshore oil drilling and mineral exploring taking place

Looking past the part underlined, we have "in the immediate vicinity might exacerbate an already volatile situation."
So we have another action being done, thus we need to use "that" as a conjunction. Using the preposition "by" doesn't do anything to fix the issue.

egmat
Why concerned "by" is incorrect and concerned "that" is correct?
Please explain

"Concerned by" should introduce a noun: "I was concerned by their behavior." "Concerned that" should introduce a clause: "I was concerned that no one would save me any cake." If you look at the non-underlined portion, you can see that the noun phrase ("drilling and exploration") has a verb ("might exacerbate").

In short, we might say either of these things:
I was concerned by the the drilling.
I was concerned that the drilling would harm the environment.

We can't mix and match like this:
I was concerned by the drilling would hurt the environment.

That's what A and E are doing.

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