Which of the following words is closest in meaning to “Unimpeachable”?

Unimpeachable means beyond doubt or blame.

• Correct answer - above suspicion: it has the same meaning as Unimpeachable.
• beyond understanding: too difficult to grasp - wrong, it does not mean the same as Unimpeachable.
• hopeless: without hope - wrong, it does not mean the same as Unimpeachable.
• unacceptable: not allowed - wrong, it does not mean the same as Unimpeachable.