They surveyed all age groups. "R-Bar Beans are considered the best of all brands among all age groups." They're the best across the board... B tells you that there was some variance in the margin amongst age groups.
If securities law or general finance interests you, then I implore you to read Black Edge by Sheelah Kolhatkar. It's all about SAC Capital Advisors and Steven Cohen -- Sooo good!
By saying the R's column is just an attempt to please her loyal readers the author is calling R's motives into question. The author previously disagrees with this approach and is therefore employing a tacit at one point that it elsewhere objects to (e).
@1300253424 This Reddit post from yesterday provided a nice walkthrough. https://www.reddit.com/r/LSAT/comments/p4kr5m/a_walkthrough_for_anxious_people_like_myself/?utm_source=share&utm_medium=ios_app&utm_name=iossmf