What is the end behavior of the graph? as x approaches infinity, f(x) approaches infinity. a. as x approaches negative infinity, f(x) approaches infinity. as x approaches infinity, f(x) approaches negative infinity. b. as x approaches negative infinity, f(x) approaches infinity. as x approaches infinity, f(x) approaches infinity. c. as x approaches negative infinity, f(x) approaches negative infinity. as x approaches infinity, f(x) approaches negative infinity. d. as x approaches negative infinity, f(x) approaches negative infinity.