To be above board
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To have a good height
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To be honest in any business deal
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They have no debts
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To try to be beautiful
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None of these
Above board means to be open, honest, and legitimate in one's dealings. The phrase originates from gambling, where keeping one's hands 'above the board' (table) showed that no cheating was occurring by hiding cards up one's sleeve. Other options incorrectly refer to physical height, debt status, or beauty.
The idiom "above board" means conducting business or dealings openly and honestly, without any hidden or deceptive practices — originally referring to keeping one's hands visible above a gaming table to avoid cheating. It has nothing to do with height, debt, or physical appearance, which is why those other options don't fit.