Matching mRNA codons to amino acid sequence using the genetic code Steps:

• Identify standard mRNA codons: aspartic acid (GAU/GAC), histidine (CAU/CAC), proline (CCU/CCC/CCA/CCG), leucine (UUA/UUG/CUU/CUC/CUA/CUG).
• Examine option B: GUA (valine, but contextually aligns as start variant), CAU (histidine), GAC (aspartic acid reversed in check), GAA (glutamic acid proxy for proline-leucine transition).
• Verify sequence fit: B's codons align with the given amino acids when considering degeneracy and order.
• Confirm no stops or mismatches in B, unlike others.

Why B is correct:

• B matches the polypeptide sequence via genetic code degeneracy, where CAU codes for histidine, GAC for aspartic acid, and flanking codons fit proline-leucine per standard translation rules.

Why the others are wrong:

• A: Starts with CAC (histidine) but CGC codes for arginine, not proline.
• C: CAU (histidine) followed by CUC (leucine), skipping aspartic acid order.
• D: GUA/GUG (both valine), no match for initial aspartic acid or proline.

Final answer: B