The number of times a person breathes in a minute is called as 

The respiration rate is the number of breaths a person takes per minute. The rate is usually measured when a person is at rest and simply involves counting the number of breaths for one minute by counting how many times the chest rises. Respiration rates may increase with fever, illness, and other medical conditions.
4. Respiratory rate is specified as breathing rate.

Hence, the correct answer is option B.