The fermenter is sealed off from the air except for a long narrow vent pipe, which allows carbon dioxide to escape from the fermenter. Since there is a constant flow of CO2 through the pipe, outside air is prevented from entering the fermenter, which reduces the threat of contamination by stray yeasts.
I would definitely have to think my grandmother. She has health issues, and that reminded me not to go out a lot. She also has told me even though everyone is going crazy, that in the end everything will be ok.
It will prepare anyone for success by showing them about different environmental stuff. Hope this helps :)
It looks to be that choice "A" has been cut off. If not, then C should be your answer!
