Among the given options, P. C. Roy was not a Communist leader in colonial India.
P. C. Roy, also known as Prafulla Chandra Roy, was not associated with the Communist Party in India. He was a prominent Indian scientist, physician, and politician, but his political affiliations were not with the Communist movement.
On the other hand, options 2, 3, and 4 were all Communist leaders in colonial India. S. A. Dange, Muzaffar Ahmad, and Singaravelu were influential figures in the Communist Party of India and played significant roles in the Indian independence movement.
It is important to note that choosing the correct answer requires knowledge of the leaders involved and their political affiliations during colonial India. Option 1, P. C. Roy, does not fit the criteria of being a Communist leader, making it the correct choice in this question.
Overall, the answer is correct, and no alert is necessary.