Final answer:
The normal resting heart rate for adults ranges from 60 to 100 beats per minute, with variations indicating different heart conditions like bradycardia or tachycardia.
Step-by-step explanation:
The normal resting heart rate for an adult human is generally between 60 and 100 beats per minute. Therefore, the correct answer to the original question is option (b) 60-100 times per minute. For trained athletes, however, it can be lower due to their increased cardiovascular efficiency, which is a condition known as bradycardia.
Learning about the heart's function and its cardiac rhythm is essential when studying human anatomy and physiology. The heart's beating pattern is maintained by its intrinsic conduction system and modified by the autonomic nervous system based on the body's needs.
In conditions where the heart rate is less than 60 beats per minute, it is referred to as bradycardia and when the heart rate exceeds 100 beats per minute during rest, it is called tachycardia. Such variations from the normal resting heart rate can suggest different health conditions.