The triangles in the figure below are similar.

image b125a080d0e9444e9eebf9b6644403df

Which proportion is correct?

A.
x20=96
x
20
=
9
6


B.
x20=915
x
20
=
9
15


C.
2015=x6
20
15
=
x
6


D.
x20−x=156
x
20

x
=
15
6