D because to find the area you must multiply the base by the height by 1/2. So if the base is x and the height is 12 yards less, the height can be represented by the base minus 12 which is written as x-12. Then since the formula is (1/2)bh. You plug in your values. X for the base (b), x-12 for heigh (h) and then multiply by 1/2 which would be equal to 14 therefore making the answer d
