The correct answer to the question is:
B. decline
As a person ages, their levels of cardiorespiratory fitness tend to decline. This decline is a natural part of the aging process and can be influenced by various factors such as a decrease in muscle mass, changes in metabolism, and decreased efficiency of the heart and lungs. Regular exercise and a healthy lifestyle can help slow down this decline and maintain better cardiorespiratory fitness as we age. It's important to stay active and engage in physical activities that promote cardiovascular health to counteract the natural decline that occurs with aging.
