C. random variables
A random variable is a variable whose values are determined by chance. A random variable is a function that associates a real number with each element in the sample space. ... The assignment of probability to each value is referred to as the probability distribution.
answer: 1, 3 and 5 are correct
this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.