Which of the following statements about the resolution of macro variable references is false?

a.   Two ampersands resolve to one ampersand.

b.   If more than four consecutive ampersands precede a name token, the macro processor generates an error message.

c.   Re-scanning continues until there are no remaining macro triggers that the macro processor can resolve.

d.   The macro processor always re-scans a name token that is preceded by multiple ampersands or by multiple percent signs.

答案是C，但C很明显是对的，答案应该是B，不管你放几个ampersand都没问题，SAS一个一个解析就是了，所以连续四个ampersands会大致错误信息的说法是不对的。大家可以试一下