A lesson in map folding

Source A: an original contemporary non-fiction-style account.

Before our navigation walk, the instructor asked us to fold a large paper map so that only the area we needed remained visible. There were eight people in the class, and most of us had arrived expecting to use our phones. We met in the park café at ten and spent the first twenty minutes indoors. The instructor explained the contour lines with a pencil, then asked us to identify the steepest part of the planned route.

Outside, we worked in pairs. I carried the map while my partner checked the compass. At the first junction we chose the wrong path, but the shape of a nearby pond helped us recognise our mistake before we went far. We returned to the junction and tried again. The walk ended at a wooden footbridge, where each pair explained one decision it had made. I took the folded map home. It had acquired a tea stain and several muddy fingerprints, none of which prevented it from being useful.

Refer to the whole of Source A. Choose the four true statements below. Write their four letters in the answer box. Choose no more than four; if more are given, only the first four distinct letters will be marked.