Ayo i think the answer is B, 10 mg/l. bc you would label the respiration rate as R, we come up with a neat little formula: NPP = GPP - R. hope this helps, have an amazing day :)
The heart rate would decrease because there is less oxygen being supplied to the cells for cellular respiration, and also your muscles won't get the blood it needs. Blood also contains oxygen and glucose which cells need to convert food to energy and to survive, so if the cells don't get blood they will die which will eventually kill the organism
