Two Real Estate Companies, Century 21 and RE/MAX, Compete with One

Two real estate companies, Century 21 and RE/MAX, compete with one another in a local market. The manager of the Century 21 office would like to advertise that homes listed with RE/MAX average more than 10 days on the market when compared to homes listed with his company. The following data shows the sample size and average number of days on the market for the two companies along with the population standard deviations.

A) Because the 80% confidence interval does not include 10, the manager at Century 21 can reject the null hypothesis and claim that homes listed with RE/MAX average more than 10 days on the market when compared to homes listed with his company.
B) Because the 80% confidence interval does not include zero, the manager at Century 21 can reject the null hypothesis and cannot claim that homes listed with RE/MAX average more than 10 days on the market when compared to homes listed with his company.
C) Because the 80% confidence interval includes 10, the manager at Century 21 can fail to reject the null hypothesis and claim that homes listed with RE/MAX average more than 10 days on the market when compared to homes listed with his company.
D) Because the 80% confidence interval includes zero, the manager at Century 21 can fail to reject the null hypothesis and claim that homes listed with RE/MAX average more than 10 days on the market when compared to homes listed with his company.