mRNA codon = GAU
anticodon = CUA
RNA, like DNA has 4 bases. 3 of them are the same as in DNA which are adenine, guanine, and cytosine. The 4th base is uracil instead of thymine as in DNA. So the CTA codon will pair with GAU. So the nRNA codon is GAU and the anticodon is CUA. As a side note, the amino acid that would be associated with this set of codons would be aspartate.