Which of the Following Is the Key Advantage of Cardiac

Which of the following is the key advantage of cardiac interbeat interval (IBI) over beats per minute (BPM) as a measure of heart rate?

A) BPM can only be measured with an x-ray or similar imaging, whereas IBI can be measured with sensors placed on the skin.
B) Far more complex data analysis is required to calculate BPM than IBI.
C) IBI is only influenced by sympathetic activation, whereas BPM is influenced by both sympathetic and parasympathetic activation.
D) Changes in IBI can be measured on a finer scale than changes in BPM.