In reservoir-type transdermal DDS, how many of the following statements are correct?

• A. ALL statements are correct
• B. ONLY ONE statement is correct
• C. TWO statements are correct
• D. THREE statements are correct

Answer: (A)

These statements form a self-referential puzzle about how many of them are true. If the claim that all statements are correct were true, then the statement that only one statement is correct would also have to be true, which is impossible because it says not all are correct. So that option cannot hold. If exactly one statement is true, the only self-consistent setup is that the unique true one is the claim that exactly one statement is correct, while the others are false. This matches the count without causing any contradictions. If two statements were true, the statement about two being correct would be true, but that would force contradictions with the others’ claims about counts. The same kind of contradiction arises if three statements were true. Therefore, the consistent conclusion is that exactly one statement is correct, namely the one that asserts that exactly one statement is correct.