Step 1: An idiom (मुहावरा) is not understood by its literal words. Here, the numbers 9 + 2 = 11 give no useful meaning. Step 2: The idiom "नौ दो ग्यारह होना" means to run away quickly, to flee. Step 3: Sentence: "पुलिस को देखते ही चोर नौ दो ग्यारह हो गए।" (The thieves ran away on seeing the police.) Step 4: The other options do not fit this idiom. Answer: To run away / disappear quickly (भाग जाना).