Non-Zero Complex Numbers are Closed under Multiplication/Proof 1

Proof
Recall that Complex Numbers form Field under the operations of addition and multiplication.

By definition of a field, the algebraic structure $\left({\C_{\ne 0}, \times}\right)$ is a group.

Thus, by definition, $\times$ is closed in $\left({\C_{\ne 0}, \times}\right)$.