Find the part of the given sentence that has an error in it. If there is no error, choose 'No error'.
Sneha worked really harder for this event, but unfortunately it got cancelled.

The correct answer is (c) Sneha worked really harder.
Explanation:
The error lies in the use of "really harder." The word "harder" is already a comparative form, so adding "really" makes it redundant. The correct phrase should be "really hard" or "harder."
Corrected sentence:
"Sneha worked really hard for this event, but unfortunately it got cancelled."