72. Hypothermia is the number one outdoor killer in cold weather. To make a simple lean-to, find a downed tree resting at an angle, or set a large branch securely against a standing tree, and stack smaller branches close together on one side. Layer debris, like leaves and moss, across the angled wall. Lastly, insulate yourself from the cold ground–which will draw heat from your warm body–by layering four to six inches of debris to lie on. Which outdoor survival skill best match above scenario? (A) Locating a suitable campsite (B) Building a shelter (C) Starting a fire (D) Finding clean water