The XYZ Tool Manufacturing Company reports the following factory overhead costs at various levels of direct labor hours for the last four months: Month Direct Labor Hours, x Factory Overhead, y July 2500 hours $ 7000 August 1500 5000 September 2000 6000 October 3000 8000 Total: 9000 hours $26000 Which of the following cost functions is obtained using the high-low method? Select one: a. y = $7000 + $2.5 x b. y = $8000 + $3 x C. y = $3,000 + $2 x d. y = $5000 + $1.5 x e. y = $2000 + $2 x