Whats a controllable risk factor of infectious disease?

answer: my answer would be a) scheduling workouts with your friend for consistent days and time

explanation:

for me personally i would be much more likely to go to the gym with a friend because i wouldn't want to cancel on them or stand them up.

well when looking at this if you think about it   negativley and positivley   react with each other and when the first layer gets full they add layers it starts with 2 on the first layer and it constantly goes on until the official number is there