The answer is D. This is referred to as reflex reaction. Reflex is the instantaneous and involuntary reactions to a stimuli. Reflex arc does not pass through the brain so the reaction time is shorter than normal. This is a adaptation to increase survival.
B. To orient themselves and to find food
Since they cannot see very well or even at all in some cases, these animals use echolocation instead to orient themselves, to find where they are, and to find food.
sunlight and nutrient availability
