An organic compound $\mathrm{A}\left(\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{Cl}\right)$ on reaction with Na/diethyl ether gives a hydrocarbon which on monochlorination gives only one chloro derivative, then A is

• Correct answer
  A

  tert-butyl chloride
• B

  sec-butyl chloride
• C

  isobutyl chloride
• D

  $\mathrm{n}$ -butyl chloride

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