[单选题]
A closed organ pipe of length 0.75 m is played whe;:g fifpkl(b+ nv z/2 u)v4ums3jj ;mun the speed of sound in air fvn +5g (zaw*gucc)dno;0h i* is 340 m/s. What is the *;0 d )uavhz(5*ci wngognf+cfundamental frequency?
A. $57 \; Hz$
B. $113 \; Hz$
C. $170 \; Hz$
D. $227 \; Hz$
