Which of the Following Statements BEST Explains Why Only Pre-MRNA

Multiple Choice

Which of the following statements BEST explains why only pre-mRNA receives a 5'cap?

A) The enzyme that initiates the capping step is known to associate with RNA polymerase II, which generates pre-mRNAs.
B) Only pre-mRNAs contain proper sequences for the cap to be added on.
C) The tail of the pre-mRNA can recruit the right combination of enzymes for capping.
D) Nuclear pore complexes only recognize pre-mRNAs and allow them out to the cytoplasm for the capping process to begin.
E) rRNA and tRNAs do not exit the nucleus to receive the cap via enzymes in the cytoplasm.