Most important element that makes an RPG, an RPG?

What does make an RPG to me is if the focus on the game is to give us, the player a good roleplaying experience. The most important element is interactivity. THat is how we solve the issues. Here is an example

Your agency has requested that you obtain information. from a terminal in an underground complex. Unfortunately for you, the location of this complex is neither known to you or your agency. How you find the location of the complex is up to you. How will you find it?

1. Find and torture a member of the organization to find out the location.
2. Find a member of the organzation, then follow him until he heads home.
3. Find a less loyal member of the organization, then bribe him into giving you the location. This will be more effective if said person is drunk, beware of the fact taht he may end up lying.
4. Find a member of the organization, threaten him to give you the location.
5. Find a map, that shows the location of the organization
6. Just stumble across the complex through sheer luck, or the use of a FAQ

Of course, finding a member wont be too easy anyway, the player could try to lure him however.

After find the complex, the player may find out there are several entrances to it. Some entrances may not be available to everyone. Once inside, the player will use whatever skills, feats, attributes, items and relationships that are at his disposal (a character with excellent disguise skill may take shortcuts unavailable to everyone else, a strong character can use his strength in various ways, not just for combat). This quest will however favor those with high IT skill.

Of course, nothing is preventing the player from getting the information before the quest starts, allowing him to complete the quest instantly.