IMO AGovernment efforts to curb the poaching of elephants primarily for their ivory tusks was a success in 2005. If the efforts had not been successful, the price of domestically produced ivory goods would not have increased significantly in 2005, since the producers of ivory products do not mind buying ivory from any and all available sources within the country.
The argument in the passage would be most seriously weakens if it were true that
Cause : Govt. efforts to curb poaching
Effect : Success - price of domestically produced ivory goods increased
Carefully note the assumptions/implicit facts :
1. Prices were low earlier
2. #1 might have been the result of widely available ivory goods (as stated)
3.
People selling ivory were actually affected, i.e. they did not find an alternative to poach and yet sell the ivory elsewhere
To weaken :
1. Find an answer inline with the pre-thinking done above
2. For cause and effect questions (weaken), prove the involvement of a third factor
3.
Prove that the effect did not actually happena) Poachers started getting a significantly better bargain abroad for their ivory in and around 2005.
Correct- In line with
highlighted thoughts.
b) The demand for ivory products,
primarily decorative items, suddenly shot up in 2005 following a countrywide fashion trend.
Not a part of the passage as a whole
c) In 2005,
independent poachers joined forces to form substantially bigger groups
which could face increased government vigilance.
Out of scope/not related to the conclusion/does not weaken
d) In 2005, poachers identified an unique and untraceable technique of hunting elephants
Interesting but we do not know whether this was a success. Nothing mentioned around the sale of ivory products.
e) The producers of ivory products are always ready to pay exorbitant prices for
raw ivory since they know that they can recover their money
Acceptable fact but what if the raw ivory was not available at all?
Also, this is unrelated to the conclusion.