I'd like to know how exactly 'infinitive' modifies a noun

I'd like to know how exactly 'infinitive' modifies a noun.

1. I suggest you write out the speech you will be giving at the conference and practice it as many times as possible. When you think you're ready, gather up some people to listen to your speech, so you can have a rehearsal before the conference starts.

what's the meaning of people to listen to your speech?

(a) people who is willing to listen to your speech.

(b) people who is able to listen to your speech.

2. If you need anyone to talk with about this matter, just remember that I'm always here.

what's the meaning of anyone to talk with about this matter?

(c) anyone who is willing to talk with you about this matter.

(d) anyone that you can talk with about this matter.

I don't think there's an answer among abcd, so please let me know know to transform it to a relative clause.