The statement $F \subset D$ means that set $F$ is a subset of set $D$. For this to be true, every element in set $F$ must also be an element in set $D$.

Given:

• $F = \{t, s\}$
• $D = \{p, r, s, t\}$

Now, let's check if all elements of $F$ are in $D$:

• $t$ is in $D$
• $s$ is in $D$

Since both elements of $F$ are in $D$, it follows that $F \subset D$ is true.

Would you like more details or have any other questions?

Here are 5 related questions to consider:

1. What is the definition of a proper subset?
2. Is $G \subset F$ true or false, given the sets?
3. What is the union of sets $E$ and $F$?
4. How do you find the intersection of sets $D$ and $G$?
5. Is the set $U$ a superset of $F$?

Tip: When determining if one set is a subset of another, carefully check if every element of the smaller set is included in the larger set.