Read each sentence to find out whether there is any grammatical error in it. The error, if any will be in one part of the sentence. The letter of that part is the answer. If there is no error, the answer is 'D'. (Ignore the errors of punctuation, if any).

1. Though he stoutly persisted in denying his involvement in the case,
2. the facts made it very clear
3. that he had hand in the cruel murder of his wife.
4. No error.