That'd be air mass,I believe
"Pheromones" is the one among the following choices given in the question that these messengers are called. The correct option among all the options that are given in the question is the second option or option "B". I hope the answer has actually come to your expected help.
Both A, B, and C are found in the excretory system.
Myofibrils are in the muscle of the intestines, villi increase surface area of the intestine, and nephrons help to filter in the kidney. Osteoblasts are found in bone, so therefore is not part of the excretory system
Answer:
the answer should be DNA REPLICATION