$\text{X}\underset{170°\text{C}}{\overset{{\text{ConH}}_{\text{2}}{\text{SO}}_{\text{4}}}{\to }}\text{Y}\underset{\text{CC}{l}_4}{\overset{{\text{Br}}_2}{\to }}\text{Q}\underset{{\text{NaNH}}_{\text{2}}}{\overset{\text{alc\hspace{0.17em}KOH}}{\to }}\text{R}$.  If X is ethyl alcohol, correct statement (s) about R is/ are

A) It decolourizes Baeyer's reagent

B) It gives benzene when subjected to polymerization

C) It gives red precipitate with ammonical ${\text{Cu}}_2\text{C}{l}_2$

D) It gives ethylene on hydrogenation in the presence of Lindlar's catalyst.