John wants to prove that the paved area of the playground is hotter than the grassy area of the playground. He measures the temperature of each area at three different times of the school day and records the temperatures. He does this for five days in a row. Thomas wants to replicate John's experiment. Which statement describes a situation that could cause Thomas's data to vary from John's data?
A) Thomas uses the same equipment that John used.
B) Thomas records the temperature data on a chart.
C) Thomas measures the temperatures only on the sunny days.
D) Thomas measures the temperatures of the paved area and the grassy area.