Answer:
Outer planets: those found after the asteroid belt like Jupiter, Saturn, Uranus, Neptune, and Pluto.
should be around 60 to 70 beats for a healthy adult and 70-80 beats for a child .
A will be the answer because usually marking your exercise days will become a habit because lets say you would do a running exercise but you want to do it in a certain day well if you mark it on the calendar, it'll become a habit.
Uhh hard one... I would say no because of how people are affectionate towards each outher