Answer:
Option a.
Step-by-step explanation:
The given expression is
[tex]x^6+2x^3+1[/tex]
Splitting the middle term, it can be rewritten as
[tex]x^6+x^3+x^3+1[/tex]
[tex](x^6+x^3)+(x^3+1)[/tex]
Taking out GCF fro each parenthesis.
[tex]x^3(x^3+1)+1(x^3+1)[/tex]
[tex](x^3+1)(x^3+1)[/tex]
[tex](x^3+1)^2[/tex]
Therefore, the correct option is a.