The graph below shows three functions: Graph of function f of x equals 0.5 to the power x. Graph of function g of x is a line segment with holes at endpoints connecting negative 1.8, negative 3 and 1, 3.8. Graph of p of x is a line segment connecting negative 1.7, 2.3 and 1, negative 4.2. Which function has all real numbers as its domain? (1 point) Select one: a. Only f(x) b. Both g(x) and p(x) c. Both f(x) and g(x) d. Only p(x)