Which of the following most accurately describes the transmembrane  signaling  process  involved  in  the steroid hormone action?: (A) Action on a membrane spanning tyrosine kinase, (B) Action of a G protein, which activates or inhibits adenylyl cyclase, (C) Diffusion across the membrane  and binding to an  intracellular receptor, (D) Opening of transmembrane ion channels
Answer is C. Steroid hormones are lipid soluble and act on cytoplasmic receptors after crossing the plasma membrane.