Which nitrogenous bases are needed to complete the DNA strand pictured below? Give your answer in order, from top to bottom.
1) Cytosine, Guanine, Thymine, Adenine
2) Thymine, Adenine, Guanine, Cytosine
3) Adenine, Thymine, Guanine, Cytosine
4) Adenine, Thymine, Cytosine, Guanine