[单选题]
A 3.00-m long pipe is in a room wherh3r d9. zy off2inz u9a5v,as.e th 26bl 4efwor:hx et9a-e temperature is $20 \; ^{\circ}C$. 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
