Final answer:
A reverse process will be spontaneous if the value of ΔG is less than zero (option B).
Step-by-step explanation:
A reverse process will be spontaneous if the value of ΔG (Gibbs free energy) is less than zero (option B). This indicates that the process has a negative free energy change and will occur spontaneously in the reverse direction. Options A, C, and D are incorrect because a positive value of ΔG, ΔH, or a negative value of ΔH, respectively, indicate that the reverse process will not be spontaneous.