[单选题]
A 3.00-m long pipe is in a room where the temperatur5ps)zrxgz9e,: l *uk:e aknm8e isl-e,zb)pf .nj $20 \; ^{\circ}C$. What is the fundamental
frequency if the pipe is open at both ends?
A. $57 \; Hz$
B. $114 \; Hz$
C. $29 \; Hz$
D. none of the above
