During a high-energy athletic event, such as a sprint, most of the energy that is provided to the muscles comes from
(not glycolysis.)
a) the electron transport chain.
b) the krebs cycle.
c) fermentation.

Answer;

-Kreb's cycle

Explanation;

-Kreb's cycle is the second phase of cellular respiration, with glycolysis as the first phase and electron transport chain as the last phase.

-Glycolysis is the breakdowns of carbohydrates-either glycogen stored in the muscle and in the liver or glucose delivered in the blood-to resynthesize ATP. Pyruvate is the end result of glycolysis, may proceed in one of two directions; pyruvate can be converted to lactate and can also be shuttled into the mitochondria.

-When pyruvate is converted into lactate, ATP resynthesis is slower and it depends on the intensity and duration of motor activity. This process is called anaerobic glycolysis.  When pyruvate is transferred into mitochondria to enter the Krebs Cycle, the speed of ATP resynthesis is slower but it can last for longer time if the intensity of exercise is medium. This process is often referred to as aerobic glycolysis.

i just took the quiz it is the electron B) Transport Chain

hope this helped

trachea, alveoli, lung capillaries, arteries

not too sure but maybe in the hot springs.