Which of the following, if true, most seriously weakens the conclusion of the argument? A. Many industries switched to the greatest extent possible from high-priced oil to lower-priced alternatives throughout the 1970's. B. Total residential energy consumption was higher in the United States in 1980 than it had been in 1970 C. Many industrial users of energy had paid little attention to energy conservation prior to 1970. D. Industrial output grew less rapidly from 1970 to 1980 than it had from 1960 to 1970. E. The industries whose production dropped sharply during the 1970's included a disproportionately large number of energy-intensive industries.