For this case we have by definition, that the total surface area of a regular pyramid with a square base is given by:

Where:
p: It is the perimeter of the base
S: It's the inclination
It is the area of the base
Substituting:

ANswer:
Option B
AC is parallel to MN then triangle ABC and triangle MBN are similar and the ratio of the corresponding sides are equal...
The answer would be 4(x^6+x-3)