Answer
option A. must use it when you turn left
is correct option for this question.
Explanation:
If a street has a central lane bordered by solid yellow and broken yellow lines, you May enter this lane no more than 300 ft from the location of left turn.
to avoid accidents or any unwanted incident you may enter this lane no more than 300 ft from the location of left turn.
hence
option A. must use it when you turn left is correct option.