Which of the following is not a term used to describe exercise that the
heart work better?

Anaerobic

Explanation:

The answer to this is simple.

Root definition of Cardio: Heart Exercise. It's designed to increase your heart rate, thus improving your heart's health over time by LOWERING your bpm necessary to complete a required and specific task. . .aka heart endurance training.

Aerobic: Designed to assist and improve the body's ability  absorb and transport oxygen via the cardiovascular system. . .aka relating to the heart.

Anaerobic: Designed to DECREASE the amount of oxygen your muscles require to use energy. It essentially limits the amount of oxygen needed to break down glucose in your body, which supplies energy, which your muscles will happily devour to provide you with strength. This has absolutely nothing to do with the heart, though studies show it may be indirectly beneficial.

Cardio: We discussed this above, Cario exercise is DESIGNED to help your heart.

Cardio-Respiratory: Again, we see the word "cardio." It's paired with the word "Respiratory," which directly relates to your breathing, aka lungs. We can thus know "Cardio-Respiratory" is designed to help your heart AND your lungs, two things that still help your heart.

Your answer is definitely B, because it is the one exercise listed NOT designed to help your heart, regardless of whatever benefits it might happen to carry. This exercise type is designed to help muscle endurance and build strength, not relating to your heart ofc.

Hope this helps!!