Where Does the Energy Come from to Add a Uracil

Multiple Choice

Where does the energy come from to add a uracil to the 3' end of a transcript?

A) the energy released by allowing the uracil to complementary base pair with an adjacent thymine
B) the hydrolysis of a terminal phosphate from the incoming UTP molecule
C) the cell's supply of ATP
D) the hydrolysis of pyrophosphate from the incoming UTP molecule
E) the hydrolysis of all three phosphate groups from the incoming UTP molecule