Wheel won’t turn on car left 3 months: Rust or Brake Issue?

Apparently the person who we told to move the car every week didn’t. The left rear wheel of my (front-wheel drive) car will not turn; the right turns fine. I jacked up the car and applied considerable leverage to the wheel, but it still won’t turn. I took off the wheel itself and WD-40′d the heck out of everything in sight.

While I wait for that to soak in, it occurred to me that the problem might be brake-related. Does that make sense?

If the WD-40 doesn’t miraculously break the corrosion, what else should I try?

Update: I waited for the WD-40 to soak in,removed the tire again, tap-tapped with a hammer for a few minutes, and the wheel broke free. Leading speculation seems to be that the emergency brake cable may have been stuck…