During early adulthood, _____.

A) cardiovascular capacity can be increased with regular exercise
B) the heart muscles become more flexible, increasing the maximum heart rate
C) the cardiovascular system does not undergo any change
D) the cardiovascular system is at the highest risk of developing congenital heart diseases

Cardiovascular Capacity

The ability of the heart and lungs to supply oxygen-rich blood to the muscles during sustained physical activity.

Regular Exercise

Consistent physical activity performed to maintain or improve health and fitness.

Cardiovascular System

The body's system that consists of the heart, blood vessels, and blood, responsible for circulating blood and lymph throughout the body to supply nutrients and remove waste.