I think the answer would be D.
Moving towards the source and having the source moving towards the observer will increase frequency. With the doppler effect a higher frequency results in a higher pitch. If you take a look at my poorly drawn picture below
the person at point A will observe a higher frequency because that observer experiences more sound waves per second then the observer at point B.
fd= frequency of observer
fs= frequency of source
v= velocity of sound
vd= frequency of observer
vs=frequency of source
So having the source move towards the observer equates to more sound waves per second, which means a higher frequency. To get a higher frequency you would
subtract in the denominator.
Moving towards the source also results in more sound waves per second. So to get a higher frequency you would
add in the numerator.
So plugging in numbers you can see that the ratio would be approximately the same
340/(340-30)=1.097
(340+30)/340=1.097
If you used the exact ratio without rounding, A would be the answer.. but for the sake of the MCAT I highly doubt you would ever need to be that specific. Understanding the concept is key.