Question

multiple choice question
which produces most of your body heat?

blood flow
joint friction
exergonic chemical reactions
muscle contraction

Explanation:

Body heat is mainly produced by exergonic chemical reactions (like cellular respiration) in cells, especially in active tissues. Blood flow helps distribute heat, joint friction and muscle contraction (while they produce some heat) are not the primary overall heat - producing mechanism.

Answer:

Exergonic chemical reactions