It can’t be b because that will increase the dissolving rate
Out of all the options, only body massager which uses electric energy to move back and forth is using motor here. It is because a motor converts electrical energy to Mechanical energy and only massager obeys it among all the options.
In short, Your Answer would be Option C
Hope this helps!
Should be 8.7 m/s. Just divide 200 by 23 and round from there.
Answer: conduction
Explanation: i think so sorry if im wrong im reallly sorry