To Calculate the Heart Rate Using the 6-Second Interval X

To calculate the heart rate using the 6-second interval x 10 method:

A) count the number of large squares in a six second portion of the ECG tracing and multiply that number by the number of QRS complexes found in that same section of the ECG tracing
B) count the number of small squares between two consecutive R waves and divide 1,500 by that number
C) find the peak of an R wave that falls on a bold line, then locate the next consecutive R wave and determine the value of line to which it is closest.
D) multiply by 10 the number of QRS complexes found in a six second portion of the ECG tracing