请选择ABCD1Y1@2?7d.g.t9@0n+N/[ What are you going to do _______ this afternoon?2n;[2i/Y'_/k
A. in2n;[2i/Y'_/k
B. on2n;[2i/Y'_/k
C. /2n;[2i/Y'_/k
D. at2n;[2i/Y'_/k