challenge: What was the primary goal of the Indian Railways in procuring the WCM-5 locomotives in the early 1960s?
  
  A. To increase the voltage of the electric locomotives
  B. To replace the ageing fleet of WCG-1 and WCP-1 class locomotives
  C. To expand the fleet of locomotives on Central Railways
  D. To introduce a new type of steam locomotive
  Answer: 