Answer:
B)TAT becomes TAC
Step-by-step explanation:
since thymine(T) pairs with adenine(A), thymine(T) is replaced with uracil(U) in the RNA and guanine(G) pairs with cytosine(C)
we can find the complementary codons for each strand
the codon for TAT is AUA which codes for methionine
the codon for TAC is AUG which also codes for methionine
that means the phenotype (methionine)remains unchanged for different genotypes(TAT and TAC)