Base your answer to the question on the diagram below which represents a process that occurs in living cells

image result for what happens whenever a net force acts on an object

if an object has a net force acting on it, it will accelerate. the object will speed up, slow down or change direction. an unbalanced force (net force) acting on an object changes its speed and/or direction of motion. an unbalanced force is an unopposed force that causes a change in motion.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.