As an Interstellar Cloud of Hydrogen Gas Shrinks in Size

Multiple Choice

As an interstellar cloud of hydrogen gas shrinks in size, its rate of rotation

A) increases, because its angular momentum is conserved.
B) decreases, because its angular momentum is conserved.
C) increases, because its total energy is conserved.
D) increases, because the force of gravity strengthens as the cloud shrinks.
E) decreases, because the force of gravity strengthens as the cloud shrinks.