[单选题]
In a resonating pipe which is openqby)y jvoonr2 )+ pt-6 a3agbiym)0w rb m*.)p+x 3la jz5b 1msat both ends, there
A. are displacement nodes at each end.
B. are displacement antinodes at each end.
C. is a displacement node at one end and a displacement antinode at the other end.
D. none of the above
