The reaction occuring when chloroform is exposed to sunlight and air is shown as ${\mathrm{CHCl}}_3+\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{air}\right)\stackrel{\mathrm{Sunlight}}{\to }\mathrm{X}+\mathrm{HCl}.$    

‘X’ is toxic, it can be converted to a non toxic substance by the addition of 2-3% solution of

• A

  ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

• B

  ${\mathrm{C}}_2{\mathrm{H}}_5-\mathrm{O}-{\mathrm{C}}_2{\mathrm{H}}_5$

• C

  ${\mathrm{CH}}_3\mathrm{CHO}$

• D

  ${\left({\mathrm{C}}_2{\mathrm{H}}_5\right)}_2{\mathrm{CO}}_3$