We were told the oil gasket under the car had to be replaced and would be costly on 2007 GMC Yukon Denali

Said it would be costly because they had to drop the engine or powertrain or something, to get to the oil pan gasket

Asked by for the 2007 GMC Yukon Denali
is this an all wheel drive or 4x4?
It is not a 4 wheel drive, but if one wheel slips, others lock in.