If $\int e^{\sin x}(1+\sec x \tan x) d x=e^{\sin x} f(x)+c$, then in $0 \leq x \leq 2 \pi$, the number of solutions of $f(x)=1$ is

• A

  4
• B

  0
• Correct answer
  C

  2
• D

  3

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