A gymnast holding a rigid body posture swings around a fixed horizontal bar from Position 1 (horizontal, moving downward) through Position 2 (the lowest point) to Position 3 (horizontal on the opposite side, moving upward). Two students analyze the rotational motion between Position 1 and Position 3:

Student 1 claims that the magnitude of the torque exerted by gravity about the bar changes continuously throughout the swing.

Student 2 claims that the total work done by gravity on the gymnast from Position 1 to Position 3 is equal to zero.

Which choice correctly evaluates both students' claims and provides a valid physical justification?