The order of basicity of amines in gaseous state is :-

$3^{\circ}>2^{\circ}>\mathrm{NH}_{3}>1^{\circ}$

$1^{\circ}>2^{\circ}>3^{\circ}>\mathrm{NH}_{3}$

$\mathrm{NH}_{3}>1^{\circ}>2^{\circ}>3^{\circ}$

$3^{\circ}>2^{\circ}>1^{\circ}>\mathrm{NH}_{3}$