Read the sentence to find out whether there is any error in it or not. The error, if any, will be in one part of the sentence. The number of that part is the answer. If there is no error, the answer is (4). Ignore errors of punctuation, if any.

This is the best which the students (1) could do in such a short time - decorating the hall (2) for the inter school get together. (3) No Error (4)