Answer:
C. 5
Explanation:
The product of distances to the near and far intercepts with the circle are the same for each line segment. In the case of the tangent, those distances are the same, so you have ...
6×6 = 4×(4+x)
36 = 16 +4x . . . . eliminate parentheses
9 = 4 + x . . . . . . .divide by 4; next, subtract 4
5 = x