Lets consider each option:
option A) This neednt be because there can be a point at which the value of random variable can be greater than 5 but probablity is less than 1.
option B) This neednt be as there can be a signle point whose value is 5 with probablity 1.
option C) If all points have value less than 5, how can the expectation be equal to be ? So, this must be true.
So, answer is option (C).