Question

The following diagram shows various positions of the moon in its orbit around Earth. The image of the moon shows its phase as seen from Earth.
In which position will three-fourths of the illuminated side of the moon be visible from Earth?

A) A
B) B
C) C
D) D

Answer 1

Three-fourths of the illuminated side of the moon be visible
from Earth when the moon is at position-B.  (choice-B)


Notice the particularly egregious screw-up on the drawing at the
"Third Quarter" position.  There, the drawing shows the illuminated 
side of the moon AWAY from the sun, and the dark side of the moon
TOWARD the sun.  That's about as silly as you can get.  

Answer 2

Answer:

B) B      

Explanation:

As the moon revolves about the Earth, we see different shapes of the moon everyday.  Phases of moon occur as different portion of illuminated side of the moon is visible from the earth.

According to diagram, at position A, there is full moon phase.

At position C, the illuminated side does not face the earth, so new phase occurs.

At position D, the moon is moving from new moon phase to half moon, so it will be crescent phase.

At position B, the moon is moving from full moon to half moon phase. So at B, it will be in gibbous phase - three-fourths of the illuminated side of the moon would be visible.