How many breaths are exchanged per minute under normal circumstances?

The correct range of breaths exchanged per minute under normal circumstances is 12-20 breaths. This figure represents the average resting respiratory rate for a healthy adult at rest, reflecting the body's need for oxygen and the process of removing carbon dioxide.

In this range, the body effectively balances gas exchange, ensuring sufficient oxygen is provided to the tissues while also expelling carbon dioxide. Factors such as age, fitness level, and overall health can influence this rate, but for the majority of adults, 12-20 breaths is an accepted standard.

Other options represent respiratory rates that are either lower or higher than the normal range. For instance, a range of 10-15 breaths may apply to certain populations, such as very young children or in deeply relaxed states. Conversely, higher ranges, such as 18-25 or 20-30 breaths per minute, could indicate increased physical activity, stress, or other physiological changes that raise the demand for oxygen. These variances highlight that while breathing rates can fluctuate due to various factors, the accepted normal resting respiratory rate is 12-20 breaths per minute.