The most likely scenario is that both the rabbit and coyote populations could decrease because the original food supply (the crops and other vegetation) has decreased. As winter approaches and crops die out, available food for the rabbits diminishes, which could lead to a decline in their population. Since coyotes rely on rabbits as a food source, a decrease in the rabbit population would also likely result in a decrease in the coyote population as they struggle to find enough food.
While it's possible that the coyote population initially increased due to the abundant food supply from the rabbits, without adequate food sources, both populations will likely face challenges as winter progresses. The statement about the plants in a nearby forest decreasing to sustain the rabbit population is less plausible, as ecosystems generally do not adjust in this manner; instead, decreased rabbit numbers would likely lead to less predation pressure on plant life.