请选择ABC5w8r1c.G2x.|:x8v'S -________________? -That's Tom's ruler.9r6J.Q6g:N;s
A. Who's Tom's ruler?9r6J.Q6g:N;s
B. Whose ruler is it?9r6J.Q6g:N;s
C. What ruler is that?9r6J.Q6g:N;s