rear drum brakes on 1999 Buick Century

The car sat in my garage for 6 weeks, when I went to drive the car the rear wheels are locked.
Could this be an issue with the parking brake cable or the drums? Everything was fine prior to parking the car.

Asked by for the 1999 Buick Century
If the parking brake was set when you parked it, a cable may have frozen, which will prevent the release of the brake.