Which of the following statements provides the BEST definition of drug tolerance? Select one: adaption of a system to prolonged or continuous exposure to a drug such that there is a reduction in the response to a particular concentration of that drug the ability of a receptor, when exposed to a particular agonist, to adapt and therefore bind a wider range of ligand structures adaption of a system to prolonged or continuous exposure to a drug such that there is an increase in the response to a particular concentration of that drug the ability of a drug, with continued administration, to interact with a wider range of receptor targets and produce a greater range of adverse effects