Monique is factoring the expression 4 x + 16 x y. Her work is shown below.

Factors of 4x: 1, 2, 4, x
Factors of 16xy: 1, 2, 4, 8, 16, x, y
GCF: 4x
Factored expression: 4 x (0 + 4 y)

Which best describes the accuracy of Monique’s solution?
Monique’s solution is accurate.
Monique made an error when listing the factors, which affected the GCF and the factored expression.
Monique made an error when determining the GCF from her list of factors.
Monique made an error when writing the factored expression.