In the Afternoon,the Decibel Level of a Busy Freeway Is

Multiple Choice

In the afternoon,the decibel level of a busy freeway is 85 dB with 90 cars passing a given point every minute.Late at night,the traffic flow is only 8 cars per minute.What is the late-night decibel level?

A) 200 dB
B) 85 dB
C) 170 dB
D) 74 dB
E) 8.5 dB