Which one is grammatically correct?

Explanation: The grammatically correct sentence is Option C: An idle man cannot prosper in life. Explanation: The article 'An' is correctly used before 'idle' because it starts with a vowel sound. Option A and B are incorrect due to grammar and incorrect article usage. Option D is wrong as the phrase 'prosper life' is ungrammatical. Note: Proper use of articles and verbs ensures grammatical accuracy and clarity in English.