[求助]帮我看看这题

The use of nets at beach resorts to protect swimming areas from sharks has been criticized by environmentalists because the nets needlessly kill thousands of marine animals annually. However, environmentalists have recently discovered that an electrified cable buried beneath the periphery of swimming areas causes sharks to swim away while harming neither humans nor marine life. Hence, by installing such cables, resort communities will be able to maintain tourism while satisfying environmentalists’ concerns.

The statement concerning what the environmentalists recently discovered plays which of the following roles in the argument?

(A) A premise of the argument

(B) The conclusion of a key term in the argument

(D) A reiteration of the conclusion for the sake of emphasis

(E) A statement of the position that is being argued against

题目没有给答案。我觉得应该是一个evidence或fact支持conclusion，可是怎么5个选项没有一个象的呀，A最象，但premise不是说和evidence,fact是有区别的吗？