Which of the following produces nitrogen gas after the reaction with nitrous acid?

• A

  $\left(\mathrm{CH}_3\right)_3 \mathrm{~N}$
• B

  $\mathrm{C}_2 \mathrm{H}_5 \mathrm{NHC}_2 \mathrm{H}_5$
• C

  $\left(\mathrm{C}_2 \mathrm{H}_5\right)_3 \mathrm{~N}$
• Correct answer
  D

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

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