Sabrina has a rug with a perimeter of 18 feet. She decides to place a border around the rug so that the new length of the rug is 8 feet and the width is 4 feet. The border is the same width all the way around. The equation which represents x, the width of the border is 2(8-2x)+ 2(4-2x)=18. What is the width of the border?

a. 3/4

b. 1 1/2

c. 1 ft

d. 3 ft