Answer:
A.) mRNA
Explanation:
A.) is correct. mRNA is a single strand of RNA that is equipped with modifications that allow it to safety travel outside the nucleus to the ribosomes.
B.) is incorrect. The nucleolus is an organelle inside of the nucleus responsible for housing ribosome biogenesis process.
C.) is incorrect. The ribosomes are structures outside of the nucleus that receive the mRNA and translate its code into amino acids. In turn, this creates new proteins.
D.) is incorrect. The nuclear envelope is the lipid bilayer membrane that separates the nuclear/genetic material from the cytoplasm.