For the Pair of Similar Triangles, Find the Length of the Indicated

Multiple Choice

For the pair of similar triangles, find the length of the indicated side.
-In the upper triangle, the shortest side has length 12 , and the middle side has length 18 . In the lower triangle, the shortest side has length 8 , the middle side has length 12 , and the longest side has length 16 . Find the length, $x$ , of the longest side of the upper triangle.

A) $x = 30$
B) $x = 16$
C) $x = 23$
D) $x = 24$