The expected value of perfect information is the

Answer (D) is correct.
The expected value under uncertainty is found by multiplying the
probability of each outcome (event) by its payoff (conditional profit or
loss) and summing the products. Perfect information is the knowledge
that a future state of nature will occur with certainty. The expected value
of perfect information is the difference between the expected value under
certainty and the expected value of the optimal decision under
uncertainty. The expected value under certainty equals the sum of the
products of the profit maximizing payoffs of perfect forecasts and the
related probabilities.