A sound note of frequency 250 Hz and wavelength 1.3m is produced at a point near a hill. If the echo of the sound is received 1 second later at the point, how far away is the hill from the point?
-
A.
131.3m -
B.
162.5m -
C.
248.7m -
D.
251.3m -
E.
325.0m.