Solve the Problem $\mathrm { E }$ In an Electrical Circuit Is Given By

Multiple Choice

Solve the problem.
-The voltage $\mathrm { E }$ in an electrical circuit is given by $\mathrm { E } = 3.1 \cos 140 \pi \mathrm { t }$ , where $t$ is time measured in seconds. Find the amplitude.

A) $3.1$
B) 140
C) $6.2$
D) $140 \pi$