Check which image a region most matches

I know that a given region, let's say Region(0,0,200,200).  I know that these region either contains an A, B, C, D, or E.  I have A, B, C, D, and E as .png images.

How could I determine which image is a match in the region without doing the following, which seems very inoptimal, especially if, say, we scaled all the way to Z:

getColor(nonsenseLoc)

usePreviousSnap(true)

if exists(A.png) then ... end
if exists(B.png) then ... end
if exists(C.png) then ... end
if exists(D.png) then ... end
if exists(E.png) then ... end

There has to be a better way...