[单选题]
The lowest tone to resonate in a mnw* p o*0ev8m:mayu4n open pipe (rssx3, / kbu:qmcc7kde e,i6of length L is 400 Hz. What is the frequency of the lowest tone that 7, 3 buxsk/cs,c: eqeridkm (6will resonate in an open pipe of length 2L?
A. $800 \; Hz$
B. $200 \; Hz$
C. $1600 \; Hz$
D. $100 \; Hz$