I can't remember how my finger works

Okay, you have your right hand on the computer mouse. To click on something, you use your index finger and the left button. However, if you want to "right click" on something (to get to "properties" -- or print, or delete, or whatever), what do you do:

A. Keep your index finger on the left button, and "right click" on the right button with your middle finger? Or....
B. Slide your index finger over and use that to click on the right button?

I have no idea where I created this ponderous existential dilemma for myself. I right click probably 20 times a day, but never ever thought about it until Wednesday. Then suddenly, I started wondering "how" I actually do it. I tried it both ways, and they both felt simultaneously comfortable and normal and yet awkward and strange. Since then, every time I right click, I wonder how I've been doing it for years, and if I've even been doing it the same way every time up until I started thinking about it. (This reminded me of a movie or TV scene along the same lines, when one character asks another something similar -- perhaps if they breathe in or out when they perform a task -- but I can't recall what the show is to save my life. Perhaps the whole "index or middle" question has so discombobulated my mind that I can't retrieve a file from the typically expansive and accurate mental trivia database).

Sheesh. So what is it? Index or middle?