To find the values of trigonometric functions, we can use the acronym SOHCAHTOA, which stands for:
Because we are only looking for sin A and cos A, we'll use SOH and CAH. Remember that the positions are relative to angle A. So side BC would be the opposite and side AC would be the adjacent sides.
The answer is the third option, sin A = 24/26, cos A = 10/26.