Tay recorded the number of imported cars that drove by his house during rush hour. He collected data for 5 working days. Taye’s sister Tiffany determined that an average of 15 imported cars drove by their house. Which cannot be a cause of the variation in Taye’s and Tiffany’s estimates?

A. Taye and Tiffany collected their data in different locations.

B. Taye and Tiffany collected their data during different weeks.

C. Taye and Tiffany collected their data in different locations.

D. Taye’s and Tiffany samples were not random samples.