By referring to the Universal Declaration of Human Rights as "purely programmatic" (line 49) in nature, the author mo...

Can someone elaborate further on how to come to the answer on example 1. Specifically between B and D. if i were taking this test separate from the video, i probably would have chosen by because it specifically says that the numbers decreased compared to before the campaign. which seems to consider other alternatives and already deciphers that it was an effect from the ad - making it the correct answer on any other question. However, answer choice D, seems to be more out of scope. so what if the tax increases and the price decreases so it rules out a alternate cause? couldn't there be other causes like we see an increase in people focusing on their health, more doctors visits that advise people not to smoke, etc. It just seems for other questions this would be crossed out because answer choice B definitively says and compares it to before the ad. Thank you in advance. Its not necessarily this specific question, I more want to know why this was chosen when you could argue that choices like D also have alternative explanations in the way B was explained to be wrong