Muzafer Sherif Conducted a Study Where He Had Participants Estimate

Muzafer Sherif conducted a study where he had participants estimate how far a light 'moved' in a dark room. When participants were placed together in the dark room, he found that after several trials their estimates began to converge. What did he find happened to participants' estimates after testing them again individually?

A) Participants' estimates began to vary widely again.
B) Participants' estimates were much lower than those initially provided.
C) Participants' estimates were much lower than the group estimate.
D) Participants' estimates continued to be consistent with the group estimate.