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'.
On one occasion he persuaded me to accompany him on a trekking expedition he was planning.
No improvement
On one occasion he persuaded me to accompany him on a trekking expedition he was planning.