How do we find out the codon the anti-codon for this question..please describe the method

Dear student, For codon in mRNA, the codons are antiparallel to the template strand of DNA. For example in the above example (i)AAA which is coding strand is first converted to template strand of DNA which will be TTT because T comes opposite to A(sign convention). This is then converted into AAA in mRNA. Similarly (ii) CAC which is coding strand is first converted into template strand which is GTG because guanine comes opposite to cytosine (sign convention). This is converted to CAC in mRNA. In t-RNA codons are antiparallel to that in mRNA . For example (III) codon in mRNA is AAA so in t-RNA it will be UUU because in RNA instead of thiamine, uracil is present. Similarly (iv) where mRNA is CAC so in t-RNA it will be GUG. Thanks and regards