Which of below listed about the earth-sun-moon system is least responsible for the cyclical phases of the moon

a: the moon's surface reflect light
b: the earth's north pole points towards polaris
c: the sun provides heat and light energy
d: the moon revolves around the earth

It's B.

If the moon's surface were completely nonreflective, it would always be black.
The Sun provides light, if it didn't then we wouldn't see the light reflected off the moon.
The moon's revolution around the Earth lets light get thrown on it from different angles.

So that only leaves B.

Some of those are terribly ambiguous, but "C" would be one that has no effect on the phases of the Moon.

How's to make an intelligent guess, based out what was discussed in class and in your coursework.

Then get back to us.

the answer has to be, you guessed it, b.