Critical Reasoning

This question has already been discussed on manhatten and on BTG forum. But it is in very old posts, so posting again. Simply GMAT test makers brain is amazing.....

---------------------------------------------------------------------------

Tiger sharks are common in the waters surrounding Tenare Island. Usually tiger sharks feed on smaller sharks, but sometimes have attacked tourists swimming and surfing at Tenare's beachs. This has hurt Tenare's tourism industry, which is second only to its fishing industry in anual revenues. In order to help the economy, therefore, the mayor of the island has proposed an ongoing program to kill any tiger sharks within a mile of the beaches.
Which of the following, if true, most strongly calls into question the likelihood that implementation of the mayor's proposal will have the desired consequences?

a) Even if not all the tiger sharks that come close to the beaches are killed, the existence of the program would reassure the tourists.

b) business owners who depend on tourism will pay most of the cost of impelemting the program.

c) Tourists come to Tenare Island for its beaches, even though the island features a number of other tourist attractions.

d) The small sharks on which tiger sharks prey feed on fish that are commercially important to the island's fisheries.

e) Not all tourists who come to Tenare Island enjoy swimming or surfing.

OA Later