Answer: muscles generate heat through activity.
Explanation:
During body activities (such as walking, running, eating) the muscles of the body are contracting and relaxing, and utilizing energy compounds like glucose to produce ATP to drive these activities.
Thus, heat energy is generated in the muscles and the body temperature rises followed by sweat release from the skin
The third one and the last one.
You should ask your teacher to be sure, but I think that you teacher meant like the mode of transmission.... Like genetically inherited and such.