The function f(x)=2^x and g(x)=f(x)+k.If k=-5,what can be concluded about the graph of g(x)? the graph of g(x) is shifted horizontally a.5 units to the left of the graph of f(x)b. 5 units to the right of the graph of f(x)c.the graph is not shifted horizontally from the graph of f(x)