The diagram provided represents different global wind patterns. A is denoted as Doldrums. Doldrums are a region near the equator where the trade winds from the northern and southern hemispheres converge. In this area, the winds are weak and inconsistent, leading to calm and stagnant conditions. The name "doldrums" is derived from an old English word that means dull or sluggish, which accurately describes the lack of wind in this region.

Option 2, Trade winds, refers to the prevailing winds that blow from the subtropical high-pressure zones towards the equator in both the northern and southern hemispheres. These winds are strong and consistent, making them ideal for sailing and trade routes.

Option 3, Westerlies, are prevailing winds that blow from the west in the middle latitudes of both the northern and southern hemispheres. These winds are responsible for weather patterns and are often associated with stormy conditions.

Option 4, Easterlies, refer to winds that blow from the east, commonly found near the poles and equator. In the diagram, A represents Doldrums, which is the correct answer.