What is x^2-12x+36 in factored form?

For this case we must factor the following expression:
[tex]x ^ 2-12x + 36[/tex]
We must find two numbers that when multiplied give as a result "36" and when added together they give "-12". These numbers are:
[tex]-6-6 = -12\\-6 * -6 = 36[/tex]
Then, the factorization is given by:
[tex](x-6) (x-6) = (x-6) ^ 2[/tex]
Answer:
[tex](x-6) ^ 2[/tex]
Option A