From what is known about spring tides and neap tides, you can conclude that

a.
the sun’s gravity exerts the most power when the moon is on the opposite side of the Earth from the sun.
b.
the height of high tides varies with the phases of the moon.
c.
spring tides and neap tides affect the phases of the moon.
d.
the moon revolves around the Earth every 14 days.