For a right circular cone, if the radius is reduced to 1/5 its original size and the slant height is reduced to 1/6 its original size,what is the surface area if the original radius is 8 centimeters and the original slant height is 13 centimeters?
a. 18.63 cm squared
b. 18.74 cm squared
c. 18.84 cm squared
d. 18.93 cm squared