I don't like any of these answers. The thing is, there is definitely a place for options C and D, heartless as they sound. If someone is wallowing in toxic, self-centered loneliness, I can't make their life more enjoyable, nor can I share my happiness with them until they're willing and able to share it. My efforts will only bring me down without bringing them up. On the other hand, they might simply feel like being alone. I can identify and respect that; it isn't something I need to "make an impact on."
I think this needs an option E: Let them know that I'm available whenever they're ready to be friends. Pray for them. Keep myself emotionally and spiritually healthy so I can have something to share when the time comes.
Maybe I'm overthinking this.