What is the deceleration lane used for?

What is the deceleration lane used for?
A)For slow vehicles to drive in.
B)To overtake on the right.
C)To reduce speed when exiting a motorway.Correct
The deceleration lane is a section of the road specifically designed so that vehicles exiting a motorway or expressway can safely reduce their speed within that lane before merging onto a lower-speed road.