A student group is preparing a discussion about the challenges of transitioning to 100% alternative energy. One student brings up the issue of 'intermittency.' Which alternative energy source is most directly affected by intermittency?
A) Geothermal energy, as underground heat is constant.
B) Hydropower, which relies on consistent water flow.
C) Solar and wind energy, as they depend on weather conditions.
D) Biomass energy, which uses organic matter as fuel.