A method for producing pure copper metal involves the reaction of copper(1) sulfide with oxygen gas to give copper metal and sulfur dioxide. Suppose the yield of this reaction is 87%. What mass of a copper one consisting of 46% copper(n) sulfide must be mined in order to produce 1.0 x 10 kg (1.0 metric ton) of copper metal? Select one: a. 1.3 x 10 kg 10 kg b. 8.0 X 10 kg c. 1.4 x 10 kg . d. 1.5 X 10 kg e. 3.2 x 10 kg