Final answer:
Cytosine can be converted into uracil, which is one of the bases found in RNA.
Step-by-step explanation:
In DNA, cytosine can be converted into uracil. Uracil is one of the four nitrogenous bases found in RNA, while thymine is one of the four nitrogenous bases found in DNA.
Therefore, the answer to the question is C. Uracil.