Partial reduction of phenyl cyanide with stannous chloride and passing dry HCl gas in ether solution followed by hydrolysis of the aldimine stannic chloride with water to form benzaldehyde is called as which of the following method of preparation of benzaldehyde?

• A. Gattermann Koch synthesis
• B. Etards reaction
• C. Stephan s reaction
• D. Gattermann reaction