Which of the following vital signs is considered abnormal for an adult?

A pulse rate of 140 beats per minute is considered abnormal for an adult at rest, as the typical resting pulse rate for adults ranges from 60 to 100 beats per minute. A pulse rate above 100 beats per minute is classified as tachycardia, which can indicate various factors such as stress, anxiety, fever, or more serious underlying medical conditions.

In contrast, the other options reflect normal ranges for vital signs. Blood pressure readings of 120 mmHg over 80 mmHg fall within the normal category, often referred to as optimal or healthy blood pressure. A temperature range between 98.6 to 99.2 degrees Fahrenheit is also considered within normal limits for an adult, as it reflects the average body temperature. Additionally, a respiratory rate of 16 to 20 breaths per minute is within the normal range for adults at rest, which typically falls between 12 to 20 breaths per minute. Therefore, while the other options indicate normal vital sign parameters, a pulse rate of 140 beats per minute stands out as abnormal.