2. The mammalian support system is an
with an branches

osteocytes, nerves

Explanation:

The mammalian support system includes many of the osteocytes which are trapped within the bone matrix. The osteocytes maintain a connection through tiny channels also called canaliculi. Through these channels, the nerves pass through in the form of branches supplying water, and nutrients to the bone. This entire system is supportive of mammalian structure.

the correct answer to this question is #5