Option A: You're right, and literally the entire world is using the wrong term on single-stage compressor setups.35 years of working in large thermal coal power plants, I beg to differ. “Inter” means in between stages in this reference. You cool the charge from 1 stage only of compression….you aftercool…if you cool the charge between 2 separate stages of compression you Intercool. I have worked on 6 stage centrifugal compressors that multiple Intercoolers and an aftercooler located after compressor. Every P&ID of L* systems (IEEE) i have ever seen support this claim
Option B: You're mistaken, and the term "aftercooler" is only used in cases where theres two stage compression as the cooler "after" the first intercooler, just like in your example where there are two compressors or in my example with older aircraft that had similar setups.
Even in the case of A, there's clear consensus on the use of the term "intercooler" in the whole automotive industry where there's just one compressor stage, so its a bit moot anyway because all that matters is that people know what you are referring to.