A frog is able to leap away from a snake because danger is sensed and responded to by OA. the immune system O B. the nervous system OC. hormones OD DNA​

B. the nervous system

Explanation:

The nervous system is one of the body systems that has to do with the passing signal information to and fro the BRAIN and other sensory organs e.g eyes, nose, ears etc. The nervous system is what causes an individual organism to sense and respond to environmental stimuli by passing chemical signals to the brain and back to the site of effect.

According to this question, a frog is able to leap away from a snake because danger is sensed and responded to by the NERVOUS SYSTEM. Information in form of chemical signals (impulses) are passed across the brain of the animal of a possible threat, which then sends back information for the frog to react to such danger by leaping away.

i think the answer would d

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.