Cold weather in northern Europe

In normal years, most parts of western Europe are warm in winter and cool in summer. The reasons include: the terrain is mainly plain, the mountains run east-west, and the humid airflow in the sea is easy to penetrate; The coastline twists and turns, and the bay goes deep into the mainland, which strengthens the influence of the ocean on the climate; To the west of the Atlantic Ocean, there is&; Bsp is beneficial to warm and humid air flow from the ocean to the land.

Therefore, choose: d.