Partial credit for multiple-answer questions.

[anjones]

If the question in a quiz has multiple answers, is there a way to give the student partial credit if he or she answers one correct answer but misses the other(s)?

Example: 

4. What impact does the metaphor comparing the fire to a tower have in the excerpt?

               a. It shows that the damage was minimal because it is taller rather than broader in scope.

(correct)  b. It helps the reader visualize the immenseness of the fire.

                c. It references the first paragraphs to create an understanding of the meaning.

(correct)  d. It helps the reader feel as well as see the power in the fire.

.

If they choose one, could they get one of two points?