For night travel, the length of a valley curve should be such that the head light beam distance is the same as

For night travel, the length of a valley curve should be such that the

1.	For night travel, the length of a valley curve should be such that the head light beam distance is the same as
A.	stopping sight distance
B.	overtaking sight distance
C.	sum of (a) and (b)
D.	difference of (a) and (b)
Answer» B. overtaking sight distance