https://www.gregmat.com/problems/problem/taken-individually-which-of-the/

even if given AB we can find the area of triangle to be (1/2) \times AB \times (AB/2) \times \tan(35) = (AB^2) \times \tan(35)/4.

Here I am assuming since tan35 is a standard constant we can find it by ourselves.

Moreover, when given, AC we can use sin(35) to find height then use AC and perpendicular height in the Pythagoras theorem to find base and then the area of the triangle in terms of AC only.

The only reason why these answers were not right i could think of is tan 35 and sin 35 is assumed to be not a constant.