being able to与to be able to

有读者问一道选择题：

Real wealth is_________avoid doing what one would rather not.

A. being able to　B. to be able to

为何应选A而不选B?

A是动名词，没有时间概念，B是不定式，指未来。这是一个表一客观真理的句子，无时间概念，故应选A。