Final answer:
If a spontaneous process has an unfavorable entropy change (decreasing system entropy), the total entropy can still increase if the system releases heat to the surroundings, making the surroundings absorb heat from the system.
Step-by-step explanation:
If a process is spontaneous, yet the entropy change of the process is unfavorable (meaning the entropy of the system decreases), something must compensate for this decrease to still drive the process spontaneously. According to the second law of thermodynamics, for a spontaneous process, the total entropy of the system plus the surroundings must increase or remain constant. The key to spontaneity lies in the relation ΔG = ΔH sys - T ΔS sys, where ΔG is the Gibbs free energy change. For a spontaneous process, ΔG must be negative. If the system's entropy decreases (ΔS sys < 0), the process can still be spontaneous if the enthalpy change of the system (ΔH sys) is negative and large enough in magnitude to make ΔG negative. This implies that the system released heat to the surroundings, increasing the surroundings' entropy enough to compensate for the system's entropy decrease.
Therefore, the correct answer to the student's question would be (b) The surroundings absorbed heat from the system.