JEE Main 2021 Chemistry question

Compound A is converted to B on reaction with and KOH. The compound B is toxic and can be decomposed by C. A, B and C respectively are:

• (A)primary amine, nitrile compound, conc. HCl
• (B)secondary amine, isonitrile compound, conc. NaOH
• (C)primary amine, isonitrile compound, conc. HClCorrect
• (D)secondary amine, nitrile compound, conc. NaOH