Three hydrocarbons P, Q and R have carbon which combine with hydrogen in the ratio of 3 : 2 : 1 respectively. Which of the following is incorrect about the reactions shown by P, Q and R?
A P does not undergo addition reactions.
B Both Q and R decolourise bromine water.
C Both Q and R give white precipitate with AgNO3 solution dissolved in NH4OH.
D None of these.