Answer;
B. Jumping rope
Explanation;
Jumping rope is not an anaerobic exercise but an aerobic exercise.
Anaerobic exercise is a form of high intensity exercise that increase the oxygen debt. However since the muscles require oxygen to maintain prolonged exertion, anaerobic exercises can only last for short periods of time.
Examples of anaerobic activity sprinting, high-intensity interval training, power lifting and most athletic sports.

In humans, the medulla region of the brain is mainly responsible for the regulation process of respiration. It is also called the respiratory rhythm centre. The chemosensitive area located near the respiratory centre sends signals across nerve impulses to alter the rate of expiration to eliminate compounds.
Grass would be the correct answer because grass seeds can float in the air. It grows everywhere and at any weather.