Use the Formula $i = P r t$ To Reach a Solution for the Following Problem

Multiple Choice

Use the formula $i = P r t$ to reach a solution for the following problem. How much principal, invested at 18% annual interest for 6 years, is needed to earn $4,039.20?

A) P = $3,740
B) P = $3,810
C) P = $3,730
D) P = $3,700
E) none of these