are commonly called producers

Autotrophs

Explination: They are called this because they use the energy and simple inorganic compounds to produce organic molecules.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

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.