At the End of Their Final Exam, 550 Students Answered

Multiple Choice

At the end of their final exam, 550 students answered an additional question in which they rated their instructor's teaching effectiveness, with the following results. What proportion of the students who rated their instructor as very or somewhat effective received a B or better in the class?

A) 0.345
B) 0.254
C) 0.482
D) 0.898
E) 0.644