Answer:
It's the nervous and muscular
Explanation:
Nervous system because you feel pain when you sprain your calf
Muscular system because sprains are basically just a torn ligament and ligaments are bands of fibrous tissue that connect bones to bones at joints
Not skeletal because sprains don't pretain to the bones
I know that its a lot but it's all I can give so I hope this help :)
(Maybe even name me brainliest?)