None of the answers above accurately answer the question. DNA stands for deoxyribonucleic acid and is a self-replicating material that nearly all living organisms have. DNA carries the organism's genetic information. In DNA, the neucleotides of one strand pair up with specific neucleotides of another strand.
Purine Adenine (A) always pairs with Pyrimidine Thymine (T), and Pyrimidine Cytosine (C) always pairs with Purine Guanine (G). These rules of base pairing, also known as nucleotide pairing, make it easy to immediately deduce the neucleotides of the missing strand in a pair. For a DNA sequence of ATTGCGACCGAG, you would find the corresponding DNA sequence of TAACGCTGGCAC.