What does DNA contain?

the chromosomes that build proteins

the coded blueprint for life

the ability to translate RNA code

the factors for heredity called alleles

DNA is like a blueprint telling enzymes and acids like RNA and mRNA what to do with its "code." The first option is not correct because the situation is actually vice versa. Chromosomes are made up of DNA and proteins; DNA is not made up of chromosomes and proteins. There are 23 pairs of chromosomes in the human cell. In that cell there is also DNA and ribosomes that make up proteins. Option three is not entirely true because, well, if the option is referring to the process of transcription, then it is mRNA that translated DNA's code not RNA's. The fourth option is also wrong because alleles are located in parts of chromosomes. Thus, the second option is the correct option because the option both makes sense and is what DNA contains.