Triangle A-C-D has a line segment B-E from side A-C to side A-D. B-E is parallel to C-D. A-B is 6, B-C is 3, A-E is 12 and E-D is x.

Carl is attempting to find the value of . He set up the proportion


. If Carl is correct, what should his answer be? If Carl is incorrect, what is the correct proportion and answer?
A.
Carl is correct and .

B.
Carl is correct and .

C.
Carl is incorrect because the proportion should be


and .

D.
Carl is incorrect because he cannot find due to lines BE and CD not being parallel.

B. Carl is correct and x = 6.