Maxwell-Boltzmann Distribution Broadens with Temperature Steps:

• Maxwell-Boltzmann distribution gives the fraction of molecules with kinetic energy E as proportional to √E exp(-E/kT).
• Most probable energy E_mp = ½ kT increases with T, but peak height g(E_mp) ∝ 1/T decreases as distribution spreads.
• Total molecules fixed, so number around E_mp drops due to lower peak density.
• For high E (E >> kT), fraction ∝ exp(-E/kT) rises with T, increasing molecules in high-energy tail.

Why C is correct:

• Peak density at E_mp scales as 1/T from the distribution formula, decreasing molecules there; high-energy tail grows via reduced -E/kT exponent.

Why the others are wrong:

• A: High-energy molecules increase, not decrease.
• B: Most probable energy molecules decrease, not increase; high-energy increases, not decrease.
• D: Most probable energy molecules decrease, not increase.

Final answer: C