Answer:
class teacher and student I didn't actually read it but I think it is class student
Smart Watches are taking over normal watches. They are getting WAYYY cheaper. There is one for about $14
The answer to your question is,
D) Check their pulse.
((Well, some people say to place your ear over the persons mouth and watch for a rise and fall of the chest-- but that's not an answer nor does that really go with any of the answers provided so..))
-Mabel <3