Researchers would like to assess the overall health of white pine trees in a state park. The park has a paved road that runs through the middle of the park. To select trees to assess for damage, the ranger parks at the side of the road and chooses 100 trees near the road to assess for damage. Which of the following statements best describes the bias that may arise from the results?

Because only 100 trees were selected, the overall damage of trees in the park may be underestimated.
The ranger should take another sample of trees near the road and compare it to the first sample to reduce bias.
Because a random sample of trees was chosen, the sample should provide a suitable estimate of the overall health of the trees.
Trees near the road may have more damage than trees away from it, so the results may overestimate the overall damage of the trees.