Who can use the 60- or 70-hour limit?

a. all drivers can use the 60-hour limit toward their driving and on-duty time when instructed to do so by their carrier.
b. only drivers with carriers that have a cmv in operation every day of the week can use the 70-hour limit.
c. anyone with permission from their carrier can use either limit.
d. eligible carriers must give permission to drivers to use the 70-hour limit.