The correct option is
B Woman, truck driver, man, car driver
As there is a relative motion between source of sound and observer, therefore, Doppler's effect comes into play
let f=original frequency of sound ,
v=velocity of sound in air,
vo=velocity of observer ,
vs=velocity of source ,
f′=apparent frequency of sound
When car driver observes the siren he will receive the frequency
f′=f(v+vov−vs) .....eq1 , gives that f′>f because v+v0>v−vs
where , source and observer both are approaching each other
When man observes the siren he will receive the frequency f′=f(vv−vs) .......eq2 gives that f′>f because v>v−vs
by above two equations we get f′>f but in eq1 the numerator is greater than the numerator in eq2 , therefore car driver observes greater frequency than standing man
where , source is approaching the observer and observer is at rest
When woman observes the siren she will receive the frequency f′=f(vv+vs) ...........eq3 gives that f′<f because v<v−vs
where , source is going away from observer and observer is at rest
When truck driver observes the siren he will receive the frequency f′=f(vv)=f .............eq4
where, source and observer both are moving in the same direction with same velocity