Which of Following Statements Is True Regarding the Probability Distribution

Multiple Choice

Which of following statements is true regarding the probability distribution for a discrete random variable X?

A) The probabilities must be nonnegative.
B) The probabilities must sum to 1.
C) The random variable must take on positive values between 0 and 1.
D) Both the probabilities must be nonnegative and the probabilities must sum to 1.
E) Both the probabilities must be nonnegative and the random variable must take on positive values between 0 and 1.