Read the descriptions of two experiments below.

experiment 1: a student did a test to see if the hardness of the soil affects the growth of sunflowers. she used a control group and experimental groups. she repeated her experiment several times and found each time that the hardness of the soil did not affect the growth.

experiment 2: a student did a test to see if the temperature of water affects the growth of cacti. she used a control group and experimental groups. her data supported her hypothesis.

which experiment is more likely to be reliable, and why?
a. experiment 2, because its results supported the hypothesis
b. experiment 1, because it gave the same results every time
c. experiment 1, because it disproved the hypothesis
d. experiment 2, because its setup included a control group