K For the given function, complete parts (a) through (f) below. f(x,y) = e (6x+6y) OB. The range is all real numbers. (c) Describe the function's level curves. Choose the correct answer below. OA. The level curves are ellipses centered at the origin. B. For f(x,y) = 0, the level curve is the x- and y-axes. For f(x,y) = 0, the level curves are hyperbolas with the x- and y-ax C. For f(x,y) = 1, the level curve is the origin. For f(x,y) = 1, the level curves are circles centered at the origin. D. The level curves are parabolas of the form y = cx (d) Find the boundary of the function's domain. Select the correct choice below and, if necessary, fill in the answer box to co OA. The boundary is (Simplify your answer. Type an equation.) B. There are no boundary points. (e) Determine if the domain is an open region, a closed region, or both. Choose the correct answer below. A. The domain is both open and closed. OB. The domain is closed. OC. The domain is open. (f) Decide if the domain is bounded or unbounded. Choose the correct answer below. OA. The domain is bounded. OB. The domain is unbounded.