The function g(x)=2^x. the function f(x)=2^x+k and k is less than 0. which of the following statements is true?
The graph of f(x) is shifted k units to the left of the graph of g(x)
The graph of f(x) is shifted k units to the right of the graph of g(x)
The graph of f(x) is shifted k units above the graph of g(x)
The graph of f(x) is shifted k units below the graph of g(x)