The greenland ice sheet contains about 3 million cubic kilometers of ice. if completely melted, this ice would release about 1.91.9 million cubic kilometers of water, which would spread out over earth's approximate 344344 million square kilometers of ocean surface. how much would the sea level rise?

0.005523 kilometer = 5.52 meter
In this case, you are asked how much the water height and given the water volume ( 1.9 million cubic kilometers) and the earth area (344milion square kilometers). 
To answer this question you just need to divide the volume with the area. The calculation would be:

Water height = volume / area= 1.9  million cubic kilometer / 344 million square kilometer = 0.005523 kilometer = 5.52 meter

It should be d if not then c