Which of the following gives positive carbylamine test?

Question

$\begin {array} {1 1} (A)\;N-Ndimethyl \: anilne & \quad (B)\;2,4 \: dimethyl\: aniline \\ (C)\;Nmethyl \: o\: methyl\: aniline & \quad (D)\;p-nitrobenzylamine \end {array}$