Refer to the Figure Below

Multiple Choice

Refer to the figure below. Part of the signal transduction mechanism common to G protein-coupled receptors is shown.Which step occurs next?

A) Extracellular signal binds to the a receptor.
B) Signal binding to a receptor causes a change in the shape in the receptor.
C) GTP bound to the G protein is exchanged for GDP.
D) The activated G protein subunit binds to an effector protein.
E) Activated cellular enzymes catalyze the formation of products, effectively amplifying the signal inside the cell.