Which among the following has lowest boiling point?

• A

  $\mathrm{CH}_3-\mathrm{O}-\mathrm{CH}_2-\mathrm{CH}_3$
• B

  $\mathrm{CH}_3-\mathrm{COOH}$
• Correct answer
  C

  $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{CH}_3$
• D

  $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{OH}$

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