Rational Numbers form Subfield of Complex Numbers

Theorem
Let $\left({\Q, +, \times}\right)$ be the field of rational numbers.

Let $\left({\C, +, \times}\right)$ be the field of complex numbers.

Then $\left({\Q, +, \times}\right)$ is a subfield of $\left({\C, +, \times}\right)$.

Proof
From Rational Numbers form Subfield of Real Numbers, $\left({\Q, +, \times}\right)$ is a subfield of $\left({\R, + \times}\right)$.

From Real Numbers form Subfield of Complex Numbers, $\left({\R, +, \times}\right)$ is a subfield of $\left({\C, + \times}\right)$.

Thus from Subfields Transitive $\left({\Q, +, \times}\right)$ is a subfield of $\left({\C, + \times}\right)$.