Final answer:
To map f(x) to g(x), vertically shift the graph of f(x) up 3 units.
Step-by-step explanation:
To map the function f(x) to g(x), we need to vertically shift the graph of f(x) up 3 units. This is because g(x) is obtained by adding 3 to f(x). By adding 3 to the y-values of f(x), we shift the entire graph vertically upward. Therefore, the correct transformation is option B - vertically shift the graph of f(x) up 3 units.