The point beyond which there is snow on the mountains all year long is the

• A. Treeline
• B. Snow line
• C. Snowfield
• D. Glacier boundary

Answer: (B)

The point where snow stays on the ground all year is the snow line. It marks the altitude where summer warmth no longer melts the snow, so slopes above remain permanently white while those below melt away in warmer months. This boundary shifts with climate and latitude, reflecting how temperature and precipitation interact with elevation. The other terms describe different ideas: the treeline is about where trees can no longer grow due to cold, not specifically about year-round snow; a snowfield is a patch of permanent snow, which can exist above the snow line but is not the transitional boundary itself; and a glacier boundary refers to the edge of a glacier, which is about ice flow and accumulation rather than the general limit of perennial snow.