Answer :
The correct answer for this question would be the third option: Object Complement. The kind of complement that is indicated by the word "hilly" is an object complement. The object of the sentence is "land". Object complement is a noun or an adjective which follows the direct object renaming or modifying it. Hope this answers the question.
Answer: The bolded word in the given sentence is "hilly" and it is an object complement.
Explanation: