challenge: What was the historical significance of the Lho La pass?
  
  A. It was a popular route for mountaineers attempting to climb Everest's West Ridge
  B. It was a trade route between Nepal and Tibet, connecting Namche Bazaar and Tingri
  C. It was a sacred pilgrimage site for Tibetan monks
  D. It was a major settlement for Nepalese and Tibetan traders
  Answer: 