Determine whether the following can be probability distributions of a random variable that can take on only the values of 0,1 , and 2 :

(a) \(f(0)=0.34 \quad f(1)=0.34\) and \(f(2)=0.34\).

(b) \(f(0)=0.2 \quad f(1)=0.6\) and \(f(2)=0.2\).

(c) \(f(0)=0.7 \quad f(1)=0.4\) and \(f(2)=-0.1\).