The Hole in the Ozone Layer Is Constantly Expanding

The hole in the ozone layer is constantly expanding. Many environmental activists express alarm that the hole will one day become large enough to make any kind of sun exposure extremely dangerous. This fear is misguided, however. We have identified activities contribute to the hole's growth and people around the world are taking positive steps to change their behavior in order to stop the growth.
The claim that the hole will one day become large enough to make any kind of sun exposure extremely dangerous plays which one of the following roles in the argument?

A) It verifies the truth of supporting evidence used for the conclusion.
B) It is a subsidiary conclusion.
C) It is a claim that the conclusion is trying to refute.
D) It is used to support the conclusion.
E) It is the main conclusion of the argument.