The correct answer is D. All of the mentioned.
A random variable is a variable whose value is uncertain, and whose possible values (outcomes) can be assigned probabilities.
The outcome from the roll of a die is a random variable, because the outcome is uncertain and the possible outcomes (1, 2, 3, 4, 5, or 6) can be assigned probabilities (1/6 for each outcome).
The outcome of flip of a coin is a random variable, because the outcome is uncertain and the possible outcomes (heads or tails) can be assigned probabilities (1/2 for each outcome).
The outcome of exam is a random variable, because the outcome is uncertain and the possible outcomes (pass or fail) can be assigned probabilities.
Therefore, all of the mentioned can be considered as random variables.