To solve this you should know that Adenine(A) pairs with Thymine(T), but in RNA thymine is replaced with Uracil(U) and Guanine(G) pairs with Cytosine(C).
The codon, present in the mRNA represents a group of three letters that is complementary to the DNA strand. The codon is a result of transcription. The anticodon is present in tRNA, the structure that transports amino acids to the protein synthesis site(ribosome) during translation. The anticodon is complementary to the codon.
It's pretty easy to interpret the codon table as the first, second and third letters are indicated.
