What are the four major subregions in Central Otago?

Context: The Central Otago wine region is broken into multiple sub-regions, each with its own climate and characteristics.

Bannockburn is a small Geographical Indication on the southern banks of the Kawarau River near Cromwell and is a very warm area that was known by gold miners as "the Heart of the Desert". Grapes ripen early on sandy, silty loam soils. The elevation ranges from 220 to 370 metres.
Bendigo lies east of the Clutha River / Mata-Au and Lake Dunstan, with grapes planted at both medium elevation and high elevation terraces. This warm area has semi arid soils at variable depths, with free draining soils at the lower levels and shallower soils at higher elevations. The Bendigo sub-region includes the vineyards at Tarras and Maori Point.
Gibbston is a tight valley enclosed by mountainous terrain. About 250 hectares of vines are planted on sloping land on the southern bank of the Kawarau River. Gibbston is the coolest and highest of the sub-regions with vineyards between 320 and 420 metres altitude. It is sometimes referred to as the Queenstown subregion.
Wānaka, the smallest of the sub-regions, has vineyards planted between the banks of Lake Wānaka and the town of Luggate to the east. Ranging between 290 to 320 metres above sea level, the vineyards have a similar but slightly warmer climate than those at Gibbston.
The Alexandra Basin is surrounded by the Clutha River / Mata-Au and Manuherikia River and regularly records New Zealand's hottest summer temperatures. Schist outcrops dominate the arid landscape. A wide diurnal shift moderates the high temperatures.
The Cromwell Basin contains the highest concentration of vines, in an area bounded by the Kawarau River, Lake Dunstan and the Pisa mountain range. It is a warm district characterised by semi arid, high terraces and moraines and gently sloping fans.

Answer: The Central Otago wine region is broken into multiple sub-regions: Bannockburn, Bendigo, Bendigo and Wānaka