1. The problem asks to identify which of the given statements is a biconditional statement. 2. A biconditional statement is a logical statement that is true when both parts have the same truth value, and false otherwise. 3. The biconditional is represented by the symbol $\leftrightarrow$ and is read as "if and only if". 4. The first statement $p \to q$ is a conditional statement, meaning "if $p$ then $q$". 5. The second statement $p \leftrightarrow q$ is a biconditional statement, meaning "$p$ if and only if $q$". 6. Therefore, the biconditional statement is $p \leftrightarrow q$. Final answer: $p \leftrightarrow q$