I agree with A and C
My personal airplane is a Grumman AA1B with the low compression 80 octane version of the LYC 0235. I run it at about 1500 RPM for about 20 seconds, do a quick left-both- right- both
mag check to make sure both mags are grounding out, and then reduce power to idle while simultaneously going to mixture ICO.
This will clear any deposits from the plugs that have accumulated on the taxi in. I also lean it on taxi. I have found this procrdure necessary on every small 80 octane engine that is being run on 100 LL gas. 100LL gas despite the low lead designation still has 4 times the amount of lead as the old 80-87 gas ( now virtually impossible to get in North America ) and will quickly foul plugs at normal taxi power settings.