1903 colt pocket barrel info

[STAGE 2]

I recently picked up a 1903 pocket in .32 and I love it. As part of my restoration I'm replacing the barrel with a new barrel from numrich, however they have 2 kinds of bushingless barrels for my specific pistol. One is for a 1/8" extractor cut and the other for a 3/32' extractor cut. On the website it says to measure extractor width between points c and d. What the heck am I supposed to measure, and which is the correct barrel?