The correct answer is C. A way to add features that aren't present in the default GIMP installation
Step-by-step explanation:
GIMP is a software or program used to manipulate images, this includes editing photographs or any other type of images. This program has multiple functions that help users to change or modify different features in images. One of the functions is script plugins, that is the option to use external programs in GIMP to add features that are not part of GIMP but can be used in GIMP through this function. Thus, script plugins are "A way to add features that aren't present in the default GIMP installation."