Answer:
Up to 60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
The urine remain in the bladder because valves prevent backflow
The answer is decay. Decay is the principal natural means of recycling solid waste.
Metabolic Syndrome is and incurable but treatable cluster of disease that cause an increase in the chance of heart attacks and heart problems.
Rheumatic disease or rheumatic disorder is an umbrella term for conditions causing chronic, often intermittent pain affecting the joints and/or connective tissue. The study of, and therapeutic interventions in, such disorders is called rheumatology
Insulin Resistance is a resistance to the hormone insulin, resulting in increasing blood sugar.
Cardio Decline is when a person starts to break down and gain more weight, causing them to lose strength. It has to do with the age of the person.
What I could see is using Cardio Decline to fill in the blank as a figure of speech, a metaphor per say. The answer is B. When they start to realize their inevitable life with their Cardio Declining, it could help them see what responsibilities they have to full fill.