AMC 8 1991 Problem 21

For every $3^\circ$ rise in temperature, the volume of a certain gas expands by $4$ cubic centimeters. If the volume of the gas is $24$ cubic centimeters when the temperature is $32^\circ$, what was the volume of the gas in cubic centimeters when the temperature was $20^\circ$? $\text{(A)}\ 8 \text{(B)}\ 12 \text{(C)}\ 15 \text{(D)}\ 16 \text{(E)}\ 40$