I believe the awnser is B
Endocrine. Because insulin is a hormone that are produced in the endocrine gland such as pancreatic gland
1. outer covering - none of the other answers can occur due to the absorbed solutions inability to reach the centre of the organism, smaller cells in greater numbers are more efficient as they can group together yet all absorb the right amounts of nutrients for its need. multi cellular organisms, such as humans can have the other answers in them as cells group together to make skin, muscles and organs. it also gives the organism to grow larger.
2. bacteria are single celled. bacteria reproduce through mitosis (cell division). bacteria break down decaying matter to obtain energy. every organism requires energy to live. Bacteria can move in order to reach their nutrient source.
Stage 3 because the person fev1 level is go down not up
