If the Rolle's theorem holds for the function $f(x) = 2x^3 + ax^2 + bx$ in the interval $[-1, 1 ]$ for the point $c = \frac{1}{2}$ , then the value of $2a + b$ is

  • [JEE MAIN 2014]
  • [JEE MAIN 2015]
  • A

    $1$

  • B

    $-1$

  • C

    $2$

  • D

    $-2$

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