Final answer:
According to DEA regulations, incineration at a high temperature is an appropriate disposal method for expired controlled prescription medication samples in the medical office.
Step-by-step explanation:
According to DEA regulations, an appropriate disposal method for expired controlled prescription medication samples in the medical office is incineration at a high temperature (>1000 degrees Celsius). This method ensures that the residues are properly destroyed and that no pharmaceutical or ecotoxic activity remains. It is important to note that even after incineration, residual ashes should be properly taken care of.