Yeah, I think that'd be called a 3-chord song in A major, Bob (from the point of view of us singer-strummer types).

But really, I can't much imagine a guitar player (picker or strummer) who knows chords at all not knowing the D chord. Em was actually the first chord I learned, for obvious reasons, followed in rapid succession by (in no particular order) C, D, and G (first song I learned was Heart of Gold, which uses those 4, IIRC). Funny to remember back to when changing with any speed at all (and on tempo) between those four was laborious and iffy. :-)

So to be honest, I'm not really getting what the point of your question is, unless the point is just to troll.

Chris