A researcher examined the effect of background noise level on memory performance of college students. Students were randomly assignment to one of two groups. Students in the first group were given a memory test in a room with a low level of background noise and students in the second group were given the memory test in a room with a high level of background noise. The memory scores of the two groups are shown below. Set alpha at .05 and determine if background noise level had a significant effect on memory scores. Low noise level scores: 8, 10, 6, 8, 10, 6 (SD = 1.788854) High noise level scores: 1, 3, 4, 7, 5, 4 (SD = 2) What is an appropriate research question for this problem? Select one: O a. Is there a difference in memory between studying with a low level of background noise or high level of background noise? O b. Is our sample mean different than our population mean? O c. Is memory better with a low level of background noise compared to a high level of background noise? O d. Is there a difference in preferred background noise between those who do good on exams and those who do poorly on exams?