Death Cap Mushrooms Produce a Substance Called Alpha-Amanitin

Death cap mushrooms produce a substance called alpha-amanitin.Alpha-amanitin efficiently blocks synthesis of mRNA,but not of tRNA or rRNA in eukaryotic organisms.How is that possible?

A) Alpha-amanitin efficiently interferes with the action of RNA polymerase I,but not RNA polymerase II or III.
B) Alpha-amanitin efficiently interferes with RNA polymerase III,but not RNA polymerase I and II.
C) Alpha-amanitin efficiently blocks the action of one or more basic transcription factors.
D) Alpha-amanitin efficiently interferes with the action of RNA polymerase II,but not RNA polymerase I or III.