The molecule that combines with proteins to form both the large and small ribosomal subunits is rRNA (option D).
Ribosomal RNA is the structural backbone of ribosomes, which is composed of RNA (ribonucleic acid).
Molecules of rRNA are synthesized in a specialized region of the cell nucleus called nucleolus, which contains the genes that encode rRNA.
Each ribosome contains at least one large rRNA and at least one small rRNA. In the nucleolus, the large and small rRNAs combine with ribosomal proteins to form the large and small subunits of the ribosome.
Therefore, it can be said that ribosomal RNA combines with proteins in the nucleus to form the small and large ribosomal subunits.
Learn more about ribosomal RNA at: https://brainly.com/question/12878512
#SPJ1
