Given:
radius of cone = r
height of cone = h
radius of cylinder = r
height of cylinder = h
slant height of cone = l
Solution
The lateral area (A) of a cone can be found using the formula:

where r is the radius and l is the slant height
The lateral area (A) of a cylinder can be found using the formula:

The ratio of the lateral area of the cone to the lateral area of the cylinder is:

Canceling out, we have:

Hence the Answer is option B