Answer:
C. Christine has been at this school for the past four years.
Explanation:
The other options unnecessarily use "has" and "had" while Answer C. is the only sentence in which it is actually necessary (ex. Dontay did most of his chores last week).
A. Burmese pythons have light-colored skin with interesting patterns.
F. The Florida Everglades make a great home for Burmese pythons.
