Solve the Equation for Solutions Over the Interval [0 $[ 0,2 \pi )$

Solve the equation for solutions over the interval [0, $[ 0,2 \pi )$ ) . Write solutions as exact values or to four decimal places, as
appropriate.
-A generator produces an alternating current according to the equation $\mathrm { I } = 40 \sin 8 \pi \mathrm { t }$ , where $\mathrm { t }$ is time in seconds and $\mathrm { I }$ is the current in amperes. What is the smallest time $t$ such that $\mathrm { I } = 20$ ?

A) $\frac { 1 } { 16 } \mathrm { sec }$
B) $\frac { 1 } { 32 } \mathrm { sec }$
C) $\frac { 1 } { 48 } \mathrm { sec }$
D) $\frac { 1 } { 24 } \mathrm { sec }$