What is the normal respiration rate for a three-month-old boy?

The normal respiration rate for a three-month-old infant typically ranges from 30 to 60 breaths per minute. In the context of the provided choices, a respiration rate of 40 fits well within this normal range. It's common for younger infants to have higher rates compared to older children and adults, as their metabolism and developmental needs are different.

While 60 breaths per minute is at the upper limit of the normal range and could still be considered acceptable, the most typical resting respiration rate in practice for three-month-olds often aligns closely with around 40 breaths per minute. This makes it a reasonable and frequently observed value among medical professionals when assessing the respiratory health of infants.