If the sum of the coefficients in the expansion of ${({\alpha ^2}{x^2} - 2\alpha {\rm{ }}x + 1)^{51}}$ vanishes, then the value of $\alpha $ is

  • [IIT 1991]
  • A

    $2$

  • B

    $-1$

  • C

    $1$

  • D

    $-2$

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