Read the sentence to find out if there is any error in it. The error if any, will be in one part is the sentence. The number of that part will be the answer. If there is no error, then the answer is (5). Ignore error of punctuation if any.

Alex asked a cup of coffee (1)/ from the waitress, (2)/ but as she had earphones in her ears, (3)/she did not respond. (4)/ No Error