Answer:
b) transcription, mRNA
Explanation:
Transcription is a process in which mRNA is produced from DNA. RNA polymerase is the enzyme that is required to make mRNA in the transcription process.
So as a peptide called alpha-amanitin kills cells by blocking the functioning of RNA polymerase therefore mRNA will not be produced because the transcription process can not proceed without RNA polymerase. So as mRNA will not produce, no protein will be produced to support the cell's functioning. So the cell will die.
Therefore the toxin will prevent transcription and the production of mRNA.