[单选题]
You are moving at 12 ,fw1j;ck0v f/gevx)v 0 esb 3f74)ngqo8t nqg 1km/h toward a stationary train. The train blows its 400-Hz whistle. Take the speed of sound to be 340 m/s. n)b1eo7gqq8 n3gf4 st What frequency do you hear?
A. $444 \; Hz$
B. $439 \; Hz$
C. $364 \; Hz$
D. $361 \; Hz$
