A stationary source of sound is emitting sound of frequency 500 Hz. Two observers A and B lying on the same line as the source, observe frequency 480 Hz and 530 Hz respectively. The velocity of A and B respectively are (in m/s), speed of sound = 300 m/s.
(1) 12, 18
(2) 8, 18
(c) 18 , 8
(d) 18, 12