If $(1+x)^n=\sum_{r=0}^n C_r x^r$, then the value of $C_0+\left(C_0+C_1\right)+\left(C_0+C_1+C_2\right)+\ldots+$ $\left(\mathrm{C}_0+\mathrm{C}_1+\mathrm{C}_2+\ldots+\mathrm{C}_{\mathrm{n}}\right)$ is

• A

  $\mathrm{n} 2^{\mathrm{n}-1}$
• B

  $2^{\mathrm{n}}+\mathrm{n}$
• C

  $(\mathrm{n}+2) 2^{\mathrm{n}}$
• Correct answer
  D

  $(\mathrm{n}+2) 2^{\mathrm{n}-1}$

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