Answer:
B
Step-by-step explanation:
The cosine is defined as an acute angle that uses a ratio of the the adjacent side over the hypotenuse.
The adjacent side is smaller of the two sides making up the reference angle (x) in this case,
The other side (the hypotenuse) is always the longest side in a right triangle.
Cos(x) = 24/26 but this reduces down to
Cos(x) = 12 / 13 which is B
