What is the correct answer and how can this be solved?

Answer:
A. 0,2,0,2
Step-by-step explanation:
Firstly, Insert 1-4 into [tex]u^n=1+(-1)^n[/tex]
[tex]u^1=1+(-1)^1\\1+(-1)1=0\\\\\\\\u^2=1+(-1)^2\\\\1+1=2\\\\\\u^3=1+(-1)^3\\\\1+(-1)^3=0\\\\\\\\u^4=1+(-1)^4\\\\1+(-1)^4=2\\[/tex]
Simple explanation, for the first number.
-1+1=0
For the second number we are saying, -1*-1=1
and then 1+1=2
For the third number we are saying, -1*-1*-1=-1
-1+1=0
For the fourth number we are saying, -1*-1*-1*-1=1
1+1=2