Choose the correct one: Laugh up one’s sleeves.

The correct answer is Laugh in one’s sleeves.

• The idiom means to laugh secretly or derisively, often at someone else's expense, without letting them know.
• While "laugh up one's sleeve" is also a commonly used variant, "laugh in one's sleeve" is a standard and correct form of the idiom.
• Option A (Laugh in one’s sleeves) uses the correct preposition 'in' for this idiom.
• Option B (Laugh at one’s sleeves) is incorrect because 'at' changes the meaning to laughing *at* the sleeves themselves, which is not the idiom.
• Option C (Laugh on one’s sleeves) is incorrect as 'on' is not the correct preposition for this idiomatic expression.
• Option D (None of these) is incorrect because 'Laugh in one’s sleeves' is a valid and correct idiom.