I choose letter A I'm not sure it is right
Answer:
The cells of multicellular organisms perform specialized tasks and communicate with one another in order to maintain homeostasis. Areas that hold that hold adjacent cells together and enable them to communicate.
Single-celled organisms maintain homeostasis using their cell membrane and other organelles.
REM sleep's function are that it helps in forming new memories, stimulates the central nervous system, and restores brain chemistry to a normal balance
