Actually, my complaint isn't that the test uses Oxford English.
My complaint is that it does not clearly state that this test is specific to Oxford English.
(I can pass it if I know in advance.)
I've translated Oxford English into American for others in the past.
I was pointing out that if you make a test specific to one or the other, it should be clearly stated prior to the test taking.
Had I been aware of it, I'd have whipped through that sucker and Bob's your uncle!
Wholeman