Answer:
B.) 7.2
Explanation:
Use the sine ratio,
, because we know the value of the hypotenuse and need to know the value opposite the given angle, 28°. Insert the values:

Solve for x. Multiply both sides by 15 to isolate x:

Enter value into calculator:

Round to the nearest tenth:

Option B is closest to the value of x.
Finito.