When studying gender differences in teen behavior, researchers have collected data implying that teenage girls use more ring tones on their cellular phones than teenage boys do. In one particular study of 40 randomly chosen teenage girls and boys (20 of each) with cellular phones, the mean number of ring tones for the girls was 3.2 with a standard deviation of 1.5. The mean for the boys was 1.7 with a standard deviation of 0.8. Conduct a hypothesis test to determine if the means are approximately the same or if the girls' mean is higher than the boys' mean. Denote the girls as "G" and the boys as "B". What is the null hypothesis?

Group of answer choices

G-B<0

G-B> 0

G-B 0

G-B=0