Why Didn't the "Plants in Operation" Curve in the Diagram

Multiple Choice

Why didn't the "plants in operation" curve in the diagram increase to the same level that the "plants on order" curve peaked?

A) Because of the increased concerns about reactor safety and waste disposal
B) Because some people were still supportive of nuclear power
C) Because nuclear power does not contribute to the greenhouse effect
D) Because there is a lag time between ordering and operating a nuclear plant
E) Because many utilities cancelled their orders