Choose the word which is different from the rest.

The answer is B. Swimming.

A. Breathing is an involuntary process that is essential for life. It is the process of taking in oxygen and expelling carbon dioxide.

C. Dancing is a form of physical expression that is often done to music. It can be a solo activity or a group activity.

D. Playing is an activity that is done for enjoyment. It can be a physical activity or a mental activity.

Swimming is a form of physical activity that is done in water. It can be a recreational activity or a competitive activity.

The other three options are all activities that can be done without water.