Option A, no contest.
It's not just the cost, time, and annoyance of commuting. It's getting up early to get ready, preparing your lunch, putting on your adult costume, etc. Plus you don't have people popping into your office unexpectedly, a boss breathing down your neck, and/or having to deal with difficult coworkers in person.
I started working from home 6 years ago and I could never imagine going back to office life.