It would be AO and BO this would be the only one with a change of Type O blood the others do not have any chance
The correct answer is mRNA.
mRNA or messenger RNA is synthesized during the process of transcription, from DNA molecule which is used as a template. mRNA contains information about protein synthesis (translation) in the form of nucleotide triplets or codons.
In the example above: reference book is DNA molecule (template for copies), copies are mRNA, wood is amino acids (building blocks) and doghouse is protein.