Perry recently noticed he is out of breath when he walks up the two flights of stairs to his family's apartment since getting his new video game system. He has been playing his game system for several hours a day since he got it six months ago. Perry never had a problem walking the stairs before and he may have an inadequate level of which health-related fitness area? (2 points)

a
Cardiovascular Endurance

b
Flexibility

c
Muscular Endurance

d
Muscular Strength