$\int \frac{(3 x-2) \tan \left(\sqrt{9 x^2-12 x+1}\right)}{\sqrt{9 x^2-12 x+1}} d x=$

• A

  $\frac{1}{3} \sec ^2 \sqrt{9 x^2-12 x+1}+c$
• B

  $\frac{1}{3} \sec ^2 x+c$
• C

  $\frac{1}{2} \log \left|\sec \sqrt{9 x^2-12 x+1}\right|+c$
• Correct answer
  D

  $\frac{1}{3} \log \left|\sec \sqrt{9 x^2-12 x+1}\right|+c$

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