18. The key difference between a continuous random variable and a discrete variable is: A. A continuous random variable can take decimal values and a discrete random variable always takes integer values. B. A continuous random variable takes infinitely many values and a discrete random variable always takes finitely many values. C. A continuous random variable takes values over an interval and a discrete random variable always takes values over a discrete set. D. A continuous random variable takes both positive and negative values and a discrete random variable always takes only positive value. E. None of the above 20. Which one of the following statements is false: A. For a continuous random variable, X, we have P(X