Consider the Ras Signal-Transduction Pathway

Consider the Ras signal-transduction pathway. Suppose a mutation occurred in the gene that encodes the transmembrane receptor to which a growth factor binds. The mutation no longer allows the growth factor to bind to the receptor. Which of the following methods could be used to overcome this mutation and allow the pathway to move forward?

A) Inject extremely high levels of growth factor into the cell.
B) Inject normal levels of nonmutated growth factor into the cell.
C) Inject only the growth factor binding domain of the transmembrane receptor into the cell.
D) Inject the activated form of Ras into the cell.
E) Inject nonmutated tumor-suppressor genes into the cell.