If N is the algebraic difference of grades, S is the minimum sight distance in metres, the length (L) of a summit curve is

• A. <img src="/_files/images/civil-engineering/highway-engineering/35-16-154-1.png">
• B. <img src="/_files/images/civil-engineering/highway-engineering/35-16-154-2.png">
• C. <img src="/_files/images/civil-engineering/highway-engineering/35-16-154-3.png">
• D. <img src="/_files/images/civil-engineering/highway-engineering/35-16-154-4.png">
• E. none of these.