Step 1: Analyze the logical expressions.
We are given that \( p \) and \( q \) are true, and \( r \) is false. Let's evaluate each option using these values:
- (A) \( (p \land q) \to r \) is false, because \( p \land q \) is true and \( r \) is false.
- (B) \( (p \to r) \to q \) is true, because \( p \to r \) is false, making the implication true regardless of \( q \).
- (C) \( (p \lor r) \lor q \) is true, because \( p \) and \( q \) are true.
- (D) \( (p \leftrightarrow q) \leftrightarrow r \) is false, because \( p \leftrightarrow q \) is true and \( r \) is false. Thus, the equivalence is false.
Step 2: Conclusion.
Thus, the correct answer is \( (p \leftrightarrow q) \leftrightarrow r \) is false, corresponding to option (D).