Correct option is B
Extra widening: - Extra width provide to Road at horizontal curve is called extra widening.
Path travelled by front axle and path travelled by rear axle it is not same on horizontal curve this phenomenon is called off tracking, so extra-widening is provided to consider off-tracking of vehicles.
It is provided for following purposes:
To avoid off tracking due to rigidity of wheel base.
To encounter psychological tendency of driver.
To increase visibility at curve.
To account lateral skidding
