
Passage: In universities, many gentle and generous teachers are good teachers, but some serious and unkind teachers are also good teachers, and all good teachers have one thing in common: they are knowledgeable people.
Question: If the above statement is true, which of the following statements must be true?
A. A.Many knowledgeable teachers are gentle and generous
B. B.Some knowledgeable teachers are serious and unkind
C. C.All knowledgeable teachers are good teachers
D. D.Some knowledgeable teachers are not good teachers
Answer: