What Is the Difference Between Ras and the G Proteins

Multiple Choice

What is the difference between Ras and the G proteins bound to G protein coupled receptors (GPCRs) ?

A) Ras is an enzyme and the G proteins bound to GPCRs are not enzymes.
B) Ras is a second messenger and the G proteins bound to GPCRs are not second messengers.
C) Ras is a small G protein and the G proteins bound to GPCRs are not small G proteins.
D) Ras can activate different effector molecules and the G proteins bound to GPCRs cannot activate different effector molecules.