The correct option is D hnRNA
RNA polymerase is an enzyme that catalyses the formation of the RNA strand from the DNA during transcription.
In eukaryotes, there are three different types of RNA polymerases.
RNA polymerase II is responsible for the transcription of heterogeneous nuclear RNA (hnRNA), which is the precursor of mRNA.
RNA polymerase I transcribes rRNA.
RNA polymerase III is responsible for the transcription of tRNA, 5srRNA and snRNA (small nuclear RNA).
Thus, the absence of RNA polymerase II will affect the synthesis of hnRNA.