Solve the Problem $\mathrm { v } = 156 \cos \left( 120 \pi \mathrm { t } - \frac { \pi } { 3 } \right)$

Solve the problem.
-The output voltage for an AC generator is approximated by $\mathrm { v } = 156 \cos \left( 120 \pi \mathrm { t } - \frac { \pi } { 3 } \right)$ . Find the smallest positive value of $\mathrm { t }$ for which the output is 106 volts. Round values to 4 decimal places.

A) $0.0110$
B) $0.0050$
C) $0.0040$
D) $0.0100$