An organic compound $(\mathrm{X})$ has an empirical formula $\mathrm{C}_4 \mathrm{H}_8 \mathrm{O}$. This gives a pale yellow precipitate with iodine in NaOH solution. What is X ?

• A

  $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{CHO}$
• Correct answer
  B

  $\mathrm{CH}_2=\mathrm{CH} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_3$
• C

  
  
• D

  $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OCH}=\mathrm{CH}_2$

Hence, the correct answer is option: 'B'.