With certain exceptions, what is the maximum number of hours a bus driver can drive in a day?
Answer: D — 13 hours
A bus driver is subject to federal regulations which limit daily driving hours to 13 hours in a day. While options A, B, and C may seem like feasible choices, they do not align with these regulations. Option A falls short of the maximum limit, option B exceeds the limit, and option C is just under the limit. Therefore, option D (13 hours) is the correct answer.