If you're aerobically fit, you can
a. run a marathon without experiencing fatigue.
b. quit your normal exercise routine without any negative effects.
c. sustain a regular routine of exercise for 30-60 minutes with minimal fatigue.
d. lift very heavy weights without injuries to your joints.

The correct answer is option C.

Explanation:

The aerobic fitness is what defines the ability of the body of an individual to take oxygen from the atmosphere and utilize it to generate energy for muscle cells. Aerobic fitness includes various factors that affect it such as cardiac function, age, genetic makeup, and lung efficiency.

This helps an individual to produce energy and provide energy to sustain a routine of exercise for 30 to 60 minutes with minimal fatigue. This is due to the ability to take enough amount of oxygen in the body for muscles.

Thus, the correct answer is option C.

proteins is the answer