y'all i feel dumb :(((( i've been doing so well during this WHOLE LR curriculum literally from the beginning but i have gotten basically all of these questions wrong. does anyone have any advice?????

can someone explain this to me??? I feel like an idiot lol I was between D and E but chose E because I thought "what does smoking have to do with anything" and was just trying to stay within the time goal. after watching the video, I now understand E (kind of) but now I somehow feel like D DOES help resolve the discrepancy??? like if half the people took BC supplements and half took placebo, then yeah....of course the group as a whole did not yield any positive/negative effects because half of them weren't even taking anything??? so my thinking is "sh*tty experiment design is a resolution for the discrepancy". am I being dense?? someone plz help lol I've read through the comments and the explanations of D being correct have not helped my understanding

as others mentioned, i'd love to see my lawhub PT data with the 7sage analytics! i've taken like 10 PTs on lawhub before i got signed up on 7sage, and i've taken the time to go through the PTs on here and just input my answers but i'd rather spend time studying than doing that. plus i like using lawhub for the sole purpose of keeping the interface/software the same (as we say in the army, "train as you fight") so as much as i love the 7sage interface, i'd rather take my PTs on lawhub but, again, i want the analytics that 7sage provides