Jason observed a large art sculpture in a local park and wanted to know its height, but the sculpture was much taller than he could measure. Jason measured the length of the shadow of the sculpture's highest point to be 15 feet long. If the top of a slide in the same park, measured at the same time of day, has a height of 90 inches and a shadow length of 54 inches, how tall is the art sculpture at its highest point?

A.
51 feet
B.
30 feet
C.
20 feet
D.
25 feet