Answer:
Signal binding causes a conformational change in the cytoplasmic portion of receptor protein
Explanation:
G-protein coupled receptors or GPCR are one of the most abundant and most common receptors present in the human body which sense a variety of stimulus from the environment.
These GPCR are located on the surface of the cell in the plasma membrane seven times and are thus called seven-transmembrane receptors.
The GPCR is associated with a G protein complex and when a ligand or stimulus binds to the receptors they cause a conformational change towards the cytoplasmic side. This conformational change transfers the GDP to G protein and a cascade of the signal begins.
Thus, the selected option is correct.