When Is/was Gravitational Contraction an Important Energy Generation Mechanism for the Sun

Multiple Choice

When is/was gravitational contraction an important energy generation mechanism for the Sun?

A) It was important when the Sun was forming from a shrinking interstellar cloud of gas.
B) It has played a role throughout the Sun's history, but it was most important right after nuclear fusion began in the Sun's core.
C) It is important during periods when the Sun is going from solar maximum to solar minimum.
D) It is the primary energy generation mechanism in the Sun today.