新手~求助一道简单的题~

 Most parents who are generous are good parents. but some self-centered parents are also good parents. Yet all good parents share one characteristic: they are good listeners

If all the statements in the passager are true, which of the following must also be true?

A. All parents who are good listeners are good parents.

B. Some parents who are good listeners are not good parents.

C. Most parents who are good listeners are generous.

D. Some parents who are good listeners are self-centered

E. Fewer self-centered parents than generous parents are good listeners.

答案是D, C和E可以理解, 但是A和B不是一对矛盾吗? 不解...我想知道some parents的范围

请各位指教~ 感谢感谢~~