(1 point) The graphs below show level sets for six different functions, where the red areas represent the the lowest heights and the purple areas are the highest heights. L -2 -3 -3L -3 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 A B C 3F -3A -3 -2 -1 0 2 -2 -1 0 1 2 -2 0 1 2 D E F Match the following functions with the proper graphs above. 1. f (x, y ) = Vx2+ 12 2. f(x, y) = 1 - x2 - yz 3. f(x, y) = 1 - Vx2 + 12 4. f ( x, y) = e-(x2 +y?) /2