Answer:
The correct answer is the letter C.
Explanation:
We can use the following trigonometric identity:
(1)
(2)
Solving each equation by b and equaling we have:


Let's recall that:
Then we have:

Using equation (1) we can find b.
Finally, we can find a using the next equation:

Therefore, the correct answer is the letter C.
I hope it helps you!