If my goal is to test whether there is any difference in grocery prices between Piggly Wiggly and Publix, which among the following statement(s) regarding study design, data collection and hypothesis test is/are correct?a. We have to make sure grocery items sampled from Piggly Wiggly are different from grocery items sampled from Publix. b. We have to make sure grocery items sampled from Piggly Wiggly are the same with grocery items sampled from Publix. c. The more data we collect, the better; because we can use 2-sample z test instead of 2-sample t test if the sample size is greater than 30.d. We should use paired t test. e. We should use 2-sample t test with unequal standard deviation. f. We should use 2-sample pooled-t test (equal standard deviation).