A machinist creates a washer by drilling a hole through the center of a circular piece of metal. If the piece of metal has a radius of x + 10 and the hole has a radius of x + 6, what is the area of the washer?

A. x^2-8pie x-64 pie

B. x^2=8pie x 64pie

C. 8pie x-64 pie

D. 8pie x + 64pie

Radius of the piece of the metal = x + 10

Radius of the hole = x + 6

Now

Area of the washer = Area of the metal - Area of the hole

= pi (x + 10) ^2 - pi (x + 6) ^2

= pi[ (x + 10) ^2 - (x + 6) ^2]

= pi (x^2 + 20x + 100 - x^2 - 12x - 36)

= pi (8x + 64)

= 8 pi x + 64 pi

From the above deduction, it can be concluded that the correct option among all the options that are given in the question is the fourth option or option "D".