Economist: Historically, sunflower seed was one of the largest production crops in Kalotopia, and it continues to be...

Hi, I understand why D is correct and B incorrect but I am confused about the stimulus itself. I picked B originally because I thought the stimulus had a temporal flaw in it (stimulus assumed that the economy would become successful given it was successful in the past). This is why I did not choose D originally because I wanted to try and pick something that had to be true. Is there actually a temporal flaw in the stimulus? If not, can you please explain an example which would be a temporal flaw? Thank you!