Write a Statement That Represents the Relationship Between the Following $C = \{ x \mid x$

Write a statement that represents the relationship between the following.
- $C = \{ x \mid x$ is a letter of the alphabet $\}$ and $D = \{ x \mid x$ is a letter in the word math $\}$

A) $\mathrm { D } \nsubseteq \mathrm { C }$
B) $\mathrm { C } \nsubseteq \mathrm { D }$
C) $\mathrm { D } \subset \mathrm { C }$
D) $\mathrm { D } = \mathrm { C }$