Some students wanted to find the number of thistle plants growing on a lawn. The students placed 10 quadrats at different positions on the lawn.

Which method should the students use to decide where to place the 10 quadrats?

A. Place the quadrats as evenly as possible around the lawn.
B. Place 5 quadrats in areas with many thistle plants and 5 quadrats in areas with only a few thistle plants.
C. Place all the quadrats randomly on the lawn.