[单选题]
In a resonating pipe which is open at bot3oe gom ,36sqdh ends, t5qh*lal4 ;0nqtrw- x1co-hx nhere
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
