An astronomical telescope has an angular magnification of magnitude $5$ for distant objects. The separation between the objective and eyepiece is $36 \, cm$ and the final image is formed at infinity. The focal lengths of the objective and eyepiece are respectively:

  • A
    $30 \, cm, 6 \, cm$
  • B
    $24 \, cm, 12 \, cm$
  • C
    $20 \, cm, 10 \, cm$
  • D
    $30 \, cm, 12 \, cm$

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