(a) phosphoric acid
DNA has 2 deoxyribose, base and a third component known as phosphoric acid. DNA (deoxyribonucleic acid) is a type of macromolecule known as a nucleic acid. It is shaped like a twisted double helix and is composed of long strands of alternating sugars and phosphate groups, along with nitrogenous bases (adenine, thymine, guanine and cytosine). It is organized into structures called chromosomes and housed within the nucleus of our cells. DNA contains the genetic information necessary for the production of other cell components and for the reproduction of life.