Don't get stressed, learn new languages, exercise regularly, look at more funny stuff.
The answer is B Avoiding a friend with whom you've recently had an argument, and spending time with friend with whom your're still on friendly terms.
Most of these I would advise you not to handle food with, but the most seriousness of these diseases is Typhoid Fever. Typhoid Fever is obtained by food an infectious person handles. The answer is C.
Viruses are very small infectious agents that only replicate in living hosts.
