Do you mean “the answers on acca website defer to BPP practice and revision kit.” or do you mean “the answers on acca website refer to BPP practice and revision kit.”
Or even do you mean “the answers on acca website differ to BPP practice and revision kit.”
Thinking about your question, I imagine that you mean “differ”
Which is the better one to study from?
I suggest BPP revision kit
(Please tell me that you’re not taking P7 next week!)