Question: Which of the following statements, regarding Ras, is incorrect?

Answers:

a) Ras is a GPCR (G protein coupled receptor)

b) Mitogenic signaling results in phosphorylation of Ras

c) the difference between wild-type, proto-oncogenic ras and mutant, oncogenic Ras is that mutant Ras is constitutively phosphorylated and activated

d) activated Ras uses GTP to phosphorylate target proteins in a kinase cascade.

e) all of the above

The answer here is all of the above. Is there a mistake in this question? It seems to me like all are true. If not, could you explain why these are not true?