The correct answer is D. keen.
Keen means eager, enthusiastic, or having a strong interest in something. In this case, the person is eager to meet foreigners and befriend them.
Anxious means worried or nervous. This is not the correct answer because the person is not worried or nervous about meeting foreigners.
Fond means having a strong liking or affection for someone or something. This is not the correct answer because the person does not have a strong liking or affection for foreigners.
Insistent means continuing to ask or demand something in a forceful way. This is not the correct answer because the person is not continuing to ask or demand to meet foreigners.