After studying the diagram that you posted above with the question and my own knowledge this is an easily answerable question.
Since I can't circle the answer in the book, I will tell you what to circle for the type of eclipse that may occur when the moon is located in position A.
You will need to circle the "solar eclipse." The reason why this type of eclipse may occur when the moon is at this particular position is because the shadow of the moon falls on the Earth during a solar eclipse. Another reason why is because the moon is aligned between the Sun and the earth.
