By "different options" he means different times and events in the Schedule and not dialog options. The way this game works is that more dialog options and events are enabled when you complete other events with the same person or others. In the Schedule, if the time slot for a person at a location is Green, it means new events have been enabled for that person at that location and time. When there are events not yet enabled (Yellow in the Schedule), you must focus on other events for that person, for other people, fill more G.A.I.A. containers, or do other non-event tasks (like find the birth control pills, etc.) and then see what events in the Schedule have now turned Green so you can now do those enabled events. Note that a lot of events are enabled by multiple events/tasks and that there is no simple do-this-to-get-that map, so be patient and turn your attention to other events or tasks to see what eventually gets enabled.
I hope that clears it up for you.