The value of the integral $\mathrm{{\rm I}}=\int e^x\left(\sin x+\cos x\right)dx$ is equal to  $e^x\cdot f\left(x\right)+C,$ $C$ being the constant of integration. Then the maximum value of $y=f\left(x^2\right), \forall x\in R$ is equal to 

• A

  $0$
• B

  $-1$
• Correct answer
  C

  $1$
• D

  $\frac{1}{2}$

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