JEE Main 2020 Chemistry question

On heating, lead (II) nitrate gives a brown gas (A). The gas (A) on cooling changes to a colourless solid/liquid (B). (B) on heating with NO changes to a blue solid (C). The oxidation number of nitrogen in solid (C) is-

• (A)+2
• (B)+3Correct
• (C)+4
• (D)+5