If an animal cell suddenly loses the ability to produce GTP, what will most likely happen to its signaling system?

A) It will not be able to activate G proteins on the cytoplasmic side of the plasma membrane.
B) It will be able to carry out reception and transduction but would not be able to respond to a signal.
C) It will use ATP instead of GTP to activate G proteins on the cytoplasmic side of the plasma membrane.
D) It will not be able to activate receptor tyrosine kinases.