An ionic compound is expected to have tetrahedral structure if $r_{+} / r_{-}$lies in the range of

• A

  $0.414$ to $0.732$
• Correct answer
  B

  $0.225$ to $0.414$
• C

  $0.155$ to $0.225$
• D

  $0.732$ to 1

Hence, the correct answer is option: 'B'.