15. Section 5.3; Problem 18 (c) A. There is an increase of 0.1428 seconds of world record 800 meter runtimes for every year elapsed. B. There is an increase of 0.1428 seconds of world record 800 meter runtimes for 385 years elapsed. C. The increase of one year causes the world record 800 meter run-time to decrease by 0.1428 seconds. D. There is a decrease of 0.1428 seconds of world record 800 meter runtimes for every year