Which of the following compounds decolourises aqueous bromine and gives white fumes of HCI on reaction with PCl₅?

Alkene decolorises Bromine water . 

$\mathrm{R}-\mathrm{CH}=\mathrm{CH}-\mathrm{R}\hspace{0.17em}\stackrel{{\mathrm{Br}}_2 \mathrm{water} \left(\mathrm{red}\right)}{\to }\mathrm{colorless}$

Alcohols gives fumes of HCl with PCl₅. 

${\mathrm{CH}}_3\mathrm{CH}={\mathrm{CHCH}}_2{\mathrm{CH}}_2\mathrm{OH}\stackrel{{\mathrm{PCl}}_5}{\to }{\mathrm{KC}}_3-\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_2-{\mathrm{CH}}_2-\mathrm{Cl}+{\mathrm{POCl}}_3 +\hspace{0.17em}\underset{\mathrm{fumes}}{\mathrm{HCl}}$

${\mathrm{CH}}_3\mathrm{CH}={\mathrm{CHCH}}_2{\mathrm{CH}}_2\mathrm{OH}$ has both C=C and -OH groups, therefore option-D is correct.