In the given question, a part of a sentence is printed in bold. Below each sentence, some phrases are given which can substitute the bold part of the sentence. Find out the phrase which can correctly substitute that part of the sentence. If the sentence is correct as it is, mark the answer as 'No correction required' or 'No Improvement'.
She should move on to the next point, and not harp one string only.
harp upon one string only
She should move on to the next point, and not harp upon one string only.