What Is the Source of the Nucleotide Triphosphates Used to Make

What is the source of the nucleotide triphosphates used to make reovirus mRNAs?

A) They are produced by enzymes inside the core virion.
B) They diffuse into the core virion from the cytoplasm.
C) RNA synthesis occurs in the cytoplasm, where the nucleotides are located.
D) The viral RNA polymerase transports them into the core virion.
E) They are brought inside the virion from the previous host cell.