According to a survey, the mean number of cell phone calls per month was 290 for 18 to 24 year olds and 194 for 45 to 54 year olds, whereas the mean number of text messages per month was 290 for 18 to 24 year olds and 57 for 45 to 54 year olds. Suppose that the poll was based on a sample of 100 18 to 24 year olds and 100 45 to 54 year olds and the standard deviation of the number of cell phone calls per month was 100 for 18 to 24 year olds and 90 for 45 to 54 year olds, whereas the standard deviation of the number of text messages per month was 90 for 18 to 24 year olds and 77 for 45 to 54 year olds.
Using a level of significance of 0.05,

A) Is there evidence of a difference in the variances of the number of cell phone calls per month for 18-24 year olds and for 45 to 54 year olds?
B) Is there evidence of a difference in the mean number of cell phone calls per month for 18-24 year olds and for 45 to 54 year olds?
C) Is there evidence of a difference in the variances of the number of text messages per month for 18-24 year olds and for 45 to 54 year olds?
D) Is there evidence of a difference in the mean number of text messages per month for 18-24 year olds and for 45 to 54 year olds?