Mutant forms of RAF have also been found to play an important role in cancer . A dominan mutant called RAF - VGOOE ( change of a valine to a...

(i think the answer might be D, but i am not sure) Please explain.

Mutant forms of RAF have also been found to play an important role in cancer . A dominanmutant called RAF - VGOOE ( change of a valine to a glutamate at amino acid position 600 ) causesRAF to become hyperactive independent of signals from Ras . Drugs that inhibit RAF - VGODEcause rapid : shrinkage of tumors that express RAF - V GODE . Interestingly , treatment of cancer cellswith these drugs leads to an increase in Ras activity in the cancer cells . Which of the followingstatements best explains this observation ?RAF normally phosphorylates the RTK and stimulates its signaling Inhibition of RAF - V GODE thereforeincreases RIK signaling and increases Ras activityERK normally phosphorylates the RTK and stimulates its signaling Inhibition of RAF - V GOOE increasesRTK signaling , which leads to increased Ras activity .ERK normally phosphorylates and inhibits RAF to restrict the duration of RTK signaling . Thereforeinhibition of ERK leads to increased Ras activity. ) ERK normally phosphorylates the RTK and inhibits its signaling Inhibition of RAF - V 6ODE decreases ERKactivity , which leads to increased RTK signaling