In order to calculate your target heart rate, you must figure out your resting heart rate.
So {A} would be the best answer.
"Pacemaker" is the one choice among the following choices given in the question that is the treatment that can also regulate heart rhythmsthat has replaced drugs in some cases. The correct option among all the options that are given in the question is the first option or option "A". I hope it helps you.
Answer:
studies sited in the report found that children are quantitatively and qualitatively different from adults in their sensitivity to pesticides and other chemicals.