What does the stuff on your T-shirt mean ?
it’s nothing .Just something _________.
考察语境俚语。A.as clear as day一清二楚；B.off the top of my head不假思索，闪念；C.under my nose在我眼皮底下（却没有发现）；D.beyond my wildest dreams出乎预料。根据语境，“没什么意思，不过是一时兴起而已”。故而选B