Final answer:
The ultimate fate of the universe, based on current evidence and the influence of dark energy, suggests that eternal expansion is the most likely scenario over the Big Crunch or a cyclic universe.
Step-by-step explanation:
According to the most recent observational evidence on the expansion rate of the universe, the ultimate fate of the universe is likely to be eternal expansion (b). The concept of a cyclic universe, which suggests an ongoing cycle of Big Bangs and Big Crunches, appears less likely now with our current understanding of dark energy. Dark energy seems to be causing the rate of expansion to accelerate, pointing away from the scenarios of a Big Crunch or a cyclic universe.
Models with sufficient dark energy imply that the universe's expansion will not halt but will continue indefinitely into the future, resulting in a universe that gets increasingly sparse, cooler, and darker over time. Thus, the evidence leans toward an open universe model where the universe expands forever, as opposed to the closed universe (Big Crunch) model. While there are still uncertainties in understanding the full implications of dark energy and other cosmological factors, the prevailing view is that of continuous expansion.