An organic compound having molecular mass `60` is found to contain `C = 20%, H = 6.67%`, and `N = 46.67%`, while rest is oxygen. On heating, it gives `NH_(3)` along with a solid residue. The solid residue gives violet color with alkaline copper sulphate solution. The compounds is
A. `CH_(3)NCO`
B. `CH_(3)CONH_(2)`
C. `(NH_(2))_(2)CO`
D. `CH_(3)CH_(2)CONH_(2)`