For a right circular cone, the lateral surface area is given by,

The value of square root of h²+r² is equal to slant height s.
So replacing the value of square root of (h²+r²) by s in the formula for lateral surface area , we have
L.S.A. = pi * r * s
where s is slant height of the given right cone.
Answer: The lateral surface area of a right cone is pi*r*s.
Option C is the correct answer.