The answer that scores no points is Ab.@ It should be noted that the post test version of this
question was worded, AThe phases of the Moon are caused by...@ The choices are identical.
(See Appendices). There are several ideas about the Moon=s phases that we inventory here.
The most prevalent misconception has to do with earth=s shadow. In general, we follow Baxter
with his notions (see Baxter, page 6).