The answer I believe is c.secondary
Answer:
A respiration rate under 12 or over 25 breaths per minute while resting is considered abnormal.
Explanation:
A person's respiratory rate is the number of breaths you take per minute. The normal respiration rate for an adult at rest is 12 to 20 breaths per minute.
Oxygen in the air can cause sliced fruit to brown, a process called enzymic browning (an oxidation reaction). Phenols and the enzyme phenolase are found in the cells of the apple, and when these are exposed to oxygen in the air, for example through slicing, the oxygen causes a reaction.
I believe the answer you are looking for is the excretory system.
