x =
A.1
B.3
C.7
Picture Provided Below

Answer:
B 3
Step-by-step explanation:
We can use the secant-secant formula:
(whole secant) x (external part) = (whole secant) x (external part)
9 * 4 = 12 *x
36 = 12x
Divide each side by 12
36/12 =12x/12
3 =x