Answer:
B
Step-by-step explanation:
Drop an altitude. Either of the two resulting right triangles with legs of length 5 and x and a hypotenuse of 10.
By the Pythagorean theorem, it follows that the answer is B.
B would be the correct answer. If you take 4:13 in order to form a ratio equal to that you have to multiply both sides of the ratio by the same number. 4*4=16 and 13*4=52