challenge: What was the 67th Guards Rifle Division's planned response to a German attack, as part of the Voronezh Front's defense plan?
  
  A. Employing its infantry to launch a preemptive assault on German positions
  B. Employing its 138th Guards Artillery Regiment, regimental guns, and mortars on the approaches to Cherkasskoe
  C. Utilizing its air support to bomb German artillery positions
  D. Retreating to a secondary defensive line to regroup and counterattack
  Answer: 