Only a correction, it's the command key, not the option one.
You can access a dialog box to set game resolution and access windowed mode by pressing and holding the Command key (⌘) when double-clicking the "The Sims 2" icon to launch the game.
On a side note, it works for Body Shop too, while it's not documented: it will show a window in which you can choose to run BS in 1024x768 resolution instead of default 800x600.