The correct answer is B. The infection most likely causes bats to wake up during hibernation.
Step-by-step explanation
According to the fragment of the question, the author said that bats need fat to feed during the hibernation from winter to spring, also they "wake up briefly once or twice a month". On the other hand, the author said "Infected bats seem to run out of fat in the middle of winter", also they "wake up from hibernation every four to five days", and "expend valuable calories flying around" According to the above, the conclusion that can be drawn about the infection is the infection probably causes bats to wake up during hibernation, because only infected bats have an abnormal hibernation cycle, also, this might be associated to the low rate of fats that are found in infected bats.