In this problem we are asked to determine which of the given questions is a statistics question that anticipates variability.
Now let us see all the given questions one by one.
In the first question we can see that "my brother's favorite car to drive" will remain same. This question doesn't represent a variable.
Likewise in the second question we can see that "my father is either going to like Mazda or Lexus". It does not include variables too.
In the third question we can see that choices of seniors in high school preferring to drive their favorite car includes variability. In this option we can see seniors choices may differ. This option includes at least a group of some seniors which will not depend on single person's choice.
If I wanted to buy a car with the lowest insurance rate also does not includes variability as it only depends on insurance rate not other factors.
Therefore, option (c) is the right choice.
