If $\frac{x^2+1}{\left(x^2+2\right)\left(x^2+3\right)}=\frac{\mathrm{A} x+\mathrm{B}}{x^2+2}+\frac{\mathrm{C} x+\mathrm{D}}{x^2+3}$, then $\mathrm{A}+\mathrm{B}+\mathrm{C}+\mathrm{D}=$

• A

  0
• Correct answer
  B

  1
• C

  -1
• D

  6

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