In Their Post-Main-Sequence Stages of Evolution High-Mass Stars Spend Progressively

Multiple Choice

In their post-main-sequence stages of evolution high-mass stars spend progressively shorter periods in each stage, in part because

A) they are losing energy faster as neutrino cooling becomes more important.
B) stellar cores become permanently inert once the stars leaves the main sequence.
C) the stars switch from fusion to fission to produce energy.
D) massive stars lose most of their nuclear fuel through powerful stellar winds.
E) the energy is now produced only via violent gravitational contractions.