Question

__________ will help you stay alert during class. A) Leaning back in your chair B) Moving your shoulders C) Holding your breath D) Sitting in the darkest part of the room

Answer 1

It should be B. moving your shoulders 
because it helps you stay alert in class better than sitting in the dark part if a room and leaning back in your chair and holding your breath
I hope I helped
Please make me brainliest

Answer 2

C) Holding your breath is a great way of staying alert

I know that by experience :)
Hope i helped!