Regarding mechanical mixers for emulsions, which statement is most accurate?

• A. None of the statements is correct
• B. One of the statements is correct
• C. Two of the statements are correct
• D. Three of the statements are correct

Answer: (D)

These four statements are a self-referential set about how many of the statements are true. Treat N as the number of true statements among them. If none were true, the first statement would be true, which is a contradiction. If exactly one is true, the only true statement must be the one that asserts exactly one statement is correct; the other three say 0, 2, or 3 are correct and would be false. That scenario is consistent, so N = 1 is possible. If two, three, or all four were true, you get contradictions: the statement about that specific count would have to be true, but the others would force a different count, making the setup inconsistent. Therefore the consistent solution is that exactly one of the statements is true, meaning the statement that claims exactly one statement is correct is the accurate one.