Final answer:
The amino acid that glycosylations take place on is asparagine, within the N-glycosylation motif (Asn-X-Ser/Thr), making option B the correct answer.
Step-by-step explanation:
The glycosylations you are referring to specifically occur on asparagine residues within the consensus sequence known as the N-glycosylation motif. The correct motif required for N-linked glycosylation is Asn-X-Ser/Thr, where 'X' can be any amino acid except proline.
Other mentioned motifs and modifications correspond to different post-translational modifications or functional sequences. For example, the RGD motif is known for its role in cell adhesion, not glycosylation. Therefore, the accurate answer to your question is: B) Asparagine; N-glycosylation motif.