Solution:(c) The old man said, O God, help me in my hour of sorrow." (Correct)(a) The old man said, O God, help me in his hour of sorrow." (Incorrect Adjective)
(b) The old man said, God must help him in his hour of sorrow."(Incorrect Sentence Structure)
(d) The old man said, O God, help him in my hour of sorrow." (Incorrect Pronoun)