Considering the reaction sequence given below, the correct statement(s) is(are):

[S] on reaction with $H_2/Pd$ in ethanol gives aniline.

[R] is salt that is stable at room temperature.

[P] gives a foul-smelling compound on reaction with  $CHC{l}_3/KOH$

[Q] on warming with water gives an organic compound that turns blue litmus red.