It can be inferred from the passage that the efficiency of model-based gold exploration depends on which of the following? I. The closeness of the match between the geological features identified by the model as critical and the actual geological features of a given area II. The degree to which the model chosen relies on empirical observation of known mineral deposits rather than on theories of ore-forming processes III. The degree to which the model chosen is based on an accurate description of the events leading to mineralization