C) All corresponding angles are congruent and all corresponding side lengths are proportional. Those prove similar figures every time.
A) can be dismissed because not every pair of sides need to be congruent (none can and you can still have similar figures), B) doesn't work because if you only have one corresponding pair each of congruent angles and corresponding congruent sides, you can't use any postulate or theorem, as you're short a corresponding pair of congruent sides (SAS, side-angle-side; SSA, side-side-angle, are possible) or congruent angles (ASA, angle-side-angle; AAS, angle-angle-side, are possible). And as for D), how do you know that you have right triangles?? You can't assume that, you gotta prove that, and there's far from enough information to do so.