An exercise scientist was testing whether the mean hours exercised per month was different between people who live in urban areas and rural areas. They sample 25 people from urban and 25 people from rural areas and wrote down the amount they exercised each month. They compute a difference of means of 4.2 hours and a 95% conference interval for the difference of means to be (-0.8, 9.2). What should they conclude at a 5% significance level? A) There is not a significant evidence because there the interval has positive and negative numbers B) There is significant evidence of a difference because the sample mean is 4.2 which is greater than 0 C) There is significant evidence because the interval has positive and negative numbers D) There is a significant evidence of a difference because the interval contains only positive numbers E) There is not significant evidence of a difference because the interval contains only positive numbers F) cannot tell without P value