A. Distractions, because it is distracting him from running.
Since there are no options listed to choose from, my best guess would be watches, since a lot of apple watch products are now sold with built in heart monitors.
I think it would be the Dance Studio. I'm sorry if I'm wrong.
I think the first and important one would be to be an example yourself in your relationship and I think equal power relations also talking to them about it also does promote equal power relations
D. it is safer because no radiation is used