I'm at 168 right now, was originally at 149 in July. What worked best for me and broke me out of my plateaus was A: drilling LG hard (it's the easiest section once you get the handle on it), and B: working on my method for RC. I'm still bad at LR, but that's because I'm dumb and argue with the answers.

We are to find the answer which best supports the archeologist's argument that "the clovis point was not invented in NA". A, out of the options, is best as although it does leave potential for your reasoning above it's the only option which gives direct evidence for the archeologist's argument.