Which of the following statements is true? a. The earnings graph of the worker with the higher hourly wage may be obtained by shifting the earnings graph of the worker with the lower hourly wage up by 870 dollars. b. The earnings graph of the worker with the higher hourly wage may be obtained by vertically stretching the earnings graph of the worker with the lower hourly wage by a factor of 870. c. The earnings graph of the worker with the higher hourly wage may be obtained by horizontally stretching the earnings graph of the worker with the lower hourly wage by a factor of 10. d. The earnings graph of the worker with the higher hourly wage may be obtained by vertically stretching the earnings graph of the worker with the lower hourly wage by a factor of 4