If $p,\;q,\;r$ are in $A.P.$ and are positive, the roots of the quadratic equation $p{x^2} + qx + r = 0$ are all real for

  • [IIT 1995]
  • A

    $\left| {\,\frac{r}{p} - 7\;} \right|\; \ge 4\sqrt 3 $

  • B

    $\left| {\;\frac{p}{r} - 7\;} \right|\; < 4\sqrt 3 $

  • C

    All $p$ and $r$

  • D

    No $p$ and $r$

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