Theo factored a greatest common factor (GCF) of 3x^2y

Question

from the expression 15x^3y^2-6x^4y^3+9x^2y^2
. What error did Theo make, if any?
Responses

Theo could have factored an additional y variable from the expression.
Theo could have factored an additional y variable from the expression.

Theo didn't make an error. He factored the correct GCF.
Theo didn't make an error. He factored the correct GCF.

Theo could have factored a higher coefficient from the expression.
Theo could have factored a higher coefficient from the expression.

Theo could have factored an additional x variable from the expression.

Answer 1

The error Theo made was not factoring out the highest possible power of x, which would be x^2. So, the correct response is:
Theo could have factored an additional x variable from the expression.