Solve the Problem $6 \mathrm {~m}$ And $3 \mathrm {~m}$ Are Connected by a Belt

Multiple Choice

Solve the problem.
-Two pulleys of diameters $6 \mathrm {~m}$ and $3 \mathrm {~m}$ are connected by a belt. The larger pulley rotates 42 times per min. Find the angular speed of the smaller pulley.

A) $126 \pi$ radians per min
B) $168 \pi$ radians per min
C) $84 \pi$ radians per min
D) $252 \pi$ radians per min