The boiling point (at atmospheric pressure) of ammonia is [tex]-28 \frac{1}{10}^\circ F[/tex] and of propylene is [tex]-53 \frac{9}{10}^\circ F[/tex]. What is the difference in their boiling points?

A. [tex]-82^\circ F[/tex]
B. [tex]26^\circ F[/tex]
C. [tex]25 \frac{4}{5}^\circ F[/tex]
D. [tex]-81 \frac{4}{5}^\circ F[/tex]