Answer:
shivering
hair on the body standing up
goosebump forming
Explanation:
The processes that help the body warm-up from the available options include the shivering of the body, formation of goosebumps on the skin, and the standing up of hairs on the body.
When the temperature of the body falls below the setpoint or the environment is cold, a homeostatic response is triggered and a signal is sent from the control center to the muscles of the body. The muscles start shaking in order to generate heat to raise the temperature of the body. At the same time, the tiny muscles at the base of the hairs on the skin contract and pull the hairs erect, causing goosebumps in the process.
