The Mechanism by Which Testosterone Alters Cell Function Is by

The mechanism by which testosterone alters cell function is by

A) binding to a receptor protein that enters the nucleus and activates specific genes.
B) binding to a transmembrane signal receptor that activates cell-signaling pathways.
C) acting as a steroid signal receptor that activates ion channel proteins.
D) serving as a second messenger that activates cell-signaling pathways.