The correct answer is 75.7°.
The figure is described as a right triangle with a hypotenuse of 85, a base of x, and an angle at the top of 63°.
We have the side opposite the angle, x, and the hypotenuse. Opposite/hypotenuse is the ratio for the sine function:
sin 63° = x/85
Multiply both sides by 85:
85(sin 63°) = x
75.7 = x