If one person will be doing all of the driving, hours driving a day should be considered the limit.
a. two to three
b. four or five
c. six to eight
d. ten

The answer in the space provided is letter c, six to eight. It is because six to eight hours of drive in a day is already a limit for a person who is driving in one day and is already a law in terms of driving for not only because it is prohibited but it is learned that it could cause accidents and conflicts to a person where excessive tiredness and lack of sleep could trigger when driving, causing accidents.