challenge: What was the primary radar system used for fire control and guidance in the S-125 Neva/Pechora's naval version, the M-1 Volna (SA-N-1)?
  
  A. 4R90 Yatagan radar
  B. 4R60 Yatagan radar
  C. 4R70 Yatagan radar
  D. 4R80 Yatagan radar
  Answer: 