***I WANT AN ACTUAL ANSWER DO NOT GUESS OR YOUR ANSWER WILL NOT GET GOOD RATINGS*** Muscular endurance is the ability of a muscle to repeatedly exert force against resistance. Check the appropriate examples:
Cycling 20 miles
Throwing a Javelin
Swimming a mile
Performing a squat once with max weight
Paddling a kayak for an hour

 Muscular endurance refers to the number of repetitions of a single exercise you can do without needing to stop and rest. So when you are thinking of Muscluar endurance think stamina and in that case, all of them can be correct if that is the most you can do without stopping.

the second one is wrong

explanation:

answer; i believe its the red blood cells; plz check first good luck