Given the following context:  Geologically, Portland is separated into two areas; the steeply sloping land at its north end called Underhill, and the larger, gently sloping land to the south, called Tophill. Portland stone lies under Tophill; the strata decline at a shallow angle of around 1.5 degrees, from a height of 151 metres (495 ft) near the Verne in the north, to just above sea level at Portland Bill. The geology of Underhill is different to Tophill; Underhill lies on a steep escarpment composed of Portland Sand, lying above a thicker layer of Kimmeridge Clay, which extends to Chesil Beach and Portland Harbour. This Kimmeridge Clay has resulted in a series of landslides, forming West Weares and East Weares.2.4 kilometres (1.5 mi) underneath south Dorset lies a layer of Triassic rock salt, and Portland is one of four locations in the United Kingdom where the salt is thick enough to create stable cavities. Portland Gas applied to excavate 14 caverns to store 1,000,000,000 cubic metres (3.5×1010 cu ft) of natural gas, which is one percent of the UK's total annual demand. It was proposed that the caverns should be connected to the National gas grid at Mappowder via a 37-kilometre (23 mi) pipeline. Plans had it that the surface facilities should be complete to store the first gas in 2011, and the entire cavern space available for storage in winter 2013. As part of the £350 million scheme, the Grade II listed former Old Engine Shed would be converted into a £1.5 million educational centre with a café and an exhibition space about the geology of Portland.  answer the following question:  What is the full name of the acronym UK?
A:
United Kingdom