Answer: OPTION B.
Explanation:
Below are shown some transformations for a function f(x):
1) If
, the function is shifted up "k" units.
2) If
, the function is shifted down "k" units.
In this case you have the following function, which you can call f(x):

Based on the transformations explained before, if this function is shifted down 4 units, you know that function obtained g(x) is:

Therefore, the equation that will shift the graph of the function down 4 units, is:
