The perimeter of a figure or shape is the distance around it.
The perimeter of the given path would be
9x + 10x^2 - x^3 + 4x^2 - 7x + 8 - x^2 + 9x + 12
We would collect like terms. It becomes
- x^3 + 10x^2 + 4x^2 - x^2 + 9x + 9x - 7x + 8 + 12
= - x^3 + 13x^2 + 11x + 20
The correct option is C