Answer:
D
Step-by-step explanation:
Well, f(1) is when n = 1, so if you check the graph, it shows that when n = 1, f(n) = 4. Therefore, f(1) = 4
Next, we find the pattern between each f(n) when we increase n by 1
When n = 1, f(n) = 4
When n = 2, f(n) = 20
When n = 3, f(n) = 100
Notice that when we increase n by 1, f(n) multiplies by 5
4 x 5 = 20
20 x 5 = 100
Thus, we know that the common multiple of 5, for choice D.
