Answer:
D. To hide or give shelter to.
Step-by-step explanation:
In the second paragraph of the passage, the meaning of the word "harbor" is to hide or give shelter to someone or something, typically with the implication that the harboring is done knowingly and intentionally. In the context of the passage, it refers to countries providing refuge or protection to terrorists like Osama bin Laden and Al Qaeda, despite international demands to hand them over.