Suppose that you wish to test the effect of lowering the soil ph on the number of lady ferns in an area. The researchers hypothesize that lowering the ph-level of the soil will lead to more ferns. Several plots of forest are randomly chosen and the number of lady ferns counted, before and after the soil has been treated with lime (which lowers the soil ph).

Before Treatment 10 20 13 30
After Treatment 8 15 14 30

Using the sign test, what can be concluded from this experiment?

A. We do not reject the null hypothesis.
B. We reject the null hypothesis.
C. There is no evidence that treating the soil with lime increases the number of ferns.
D. Both (a) and (c)