$f_v$ and $f_r$ are the focal lengths of a convex lens for violet and red lights respectively,and $F_v$ and $F_r$ are the magnitudes of the focal lengths of a concave lens for violet and red lights respectively. Then:

  • A
    $f_v < f_r$ and $F_v > F_r$
  • B
    $f_v < f_r$ and $F_v < F_r$
  • C
    $f_v > f_r$ and $F_v > F_r$
  • D
    $f_v > f_r$ and $F_v < F_r$

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