[单选题]
In a resonating pipe i p(a2np44;en*ea rt rwhich 8ga :ixev hrg)e8;y7i -mi.f xis open at 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
