Which among the following reactions represents the Carbylamine reaction?

• A
  $R-NH_2 + CHCl_3 + 3KOH \xrightarrow{\Delta, \text{alc.}} R-NC + 3KCl + 3H_2O$
• B
  $R-NH_2 + HNO_2 \xrightarrow{NaNO_2 + HCl} R-OH + N_2 \uparrow + H_2O$
• C
  $R-NH_2 + CH_3COCl \xrightarrow{\text{pyridine}} R-NH-COCH_3 + HCl$
• D
  $R-NH_2 + R-X \rightarrow R_4N^+ X^- + 2HX$