Over the past few years, violent crime has decreased dramatically in City X. During this period, there has also been an increase in the number of late-night street vending licenses granted by the city, thereby increasing the number of people on the streets at night. Therefore, the reduction in violent crime must be related to increase in vending licenses.
Which of the following if true would cast doubt on the argument above?

A. The amount of nonviolent crime in City X has not changed much over the past few years.
B. A reduction in crime also causes more pedestrians to be out on the streets in evenings.
C. The number of street vendors in City X has increased steadily during the period in question.
D. During the past few years, City X has reduced the amount of city taxes street vendors must pay.
E. Last year, City X increased the number of police officers working at night.
[spoiler]
IMO - C.[/spoiler]