Which of the following statements about leverage is true? 1. Operating leverage influences the top half of the income statement, dealing with the impact of changes in sales revenue on operating income II. Financial leverage influences the bottom half of the income statement, dealing with the impact of changes in operating income upon earnings per share III. Combined leverage influences the the entire income statement, dealing with the impact of changes in sales revenue upon earnings per share Select one: Al only OB. and I only a and Ill only D. I, II and