In which of the following scenarios should you choose to clone a built-in Style Guide?

In which of the following scenarios should you choose to clone a built-in Style Guide?
A . When minor customizations to the base theme should be done inside the app theme.
B . It is not possible to customize a built-in Style Guide, since it is part of OutSystems UI.
C . When you want to introduce extensive changes to an existing theme.
D . When it is not possible to benefit from any existing theme and extensive changes are needed.

Answer: C