Can I award points to more than one answer?

No, you may only select one "most helpful" answer. Dividing points among answerers has been considered previously, but discarded based on the relatively little benefit which would be gained, and the difficulty of implementing administration of points and such problems as dividing four points among three answers.

A useful guideline for cases where you cannot decide on an answer is to choose the one which helped you most. In the case of two or more equally helpful answers, you may choose the first (things tend to even out for answerers over time.)