Three numbers are in an increasing geometric progression with common ratio $\mathrm{r}$. If the middle number is doubled, then the new numbers are in an arithmetic progression with common difference $\mathrm{d}$. If the fourth term of GP is $3 \mathrm{r}^{2}$, then $\mathrm{r}^{2}-\mathrm{d}$ is equal to:

  • [JEE MAIN 2021]
  • A

    $7-7 \sqrt{3}$

  • B

    $7+\sqrt{3}$

  • C

    $7-\sqrt{3}$

  • D

    $7+3 \sqrt{3}$

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