You want to conduct a study on twenty married couples to see if there is a difference in the time spent using social media per week between husbands...

You want to conduct a study on twenty married couples to see if there is a difference in the time spent using social media per week between husbands and wives. For assessing the sample size for this study where you will be using a paired t-test for analysis, which sample size should you consider and how should you check for the normality of the data?

a.20 couples represent the sample size and you should check the differences in time spent on social media per week between spouses with a histogram. 

b.40 people represent the sample size and you should check the differences in time spent on social media per week between spouses with a histogram. 

c.20 couples represent the sample size and you should check the individual times spent per week on social media with a histogram. 

d.40 people represent the sample size and you should check the individual times spent per week on social media with a histogram.