Exposure to nitrous acid (see Section 19-16), sometimes found in cells, can convert cytosine to uracil. (a)

Question:

Exposure to nitrous acid (see Section 19-16), sometimes found in cells, can convert cytosine to uracil.
(a) Propose a mechanism for this conversion.
(b) Explain how this conversion would be mutagenic upon replication.
(c) DNA generally includes thymine, rather than uracil (found in RNA). Based on this fact, explain why the nitrous acid-induced mutation of cytosine to uracil is more easily repaired in DNA than it is in RNA.