Question: Which market town in Lancashire is part of the BB postcode area?

Context:
PR postcode area
The PR postcode area, also known as the Preston postcode area, is a group of eleven postcode districts in England, which are subdivisions of four post towns.
 These postcode districts cover the city of Preston and the towns of Leyland and Chorley in south-west Lancashire, plus the town of Southport in Merseyside.
RM postcode area
The RM postcode area, also known as the Romford postcode area, is a group of 20 postcode districts in England, which are subdivisions of nine post towns.
 The majority of these postcode districts cover part of north east and east London.
 Inward mail for the RM postcode area is sorted at the Romford Mail Centre, with the E and IG postcode area mail.
SY postcode area
The SY postcode area, also known as the Shrewsbury postcode area, is a group of postcode districts primarily around Shrewsbury, but also covering Aberystwyth, Bishop's Castle, Borth, Bow Street, Bucknell, Caersws, Church Stretton, Craven Arms, Ellesmere, Llanbrynmair, Llandinam, Llanfechain, Llanfyllin, Llanidloes, Llanon, Llanrhystud, Llansanffraid, Llanymynech, Ludlow, Lydbury North, Machynlleth, Malpas, Meifod, Montgomery, Newtown, Oswestry, Talybont, Tregaron, Welshpool, Whitchurch and Ystrad Meurig.
 Despite being centred on the large English town of Shrewsbury, more than half of the postcode area is in Wales.
BB postcode area
The BB postcode area, also known as the Blackburn postcode area, is a group of postcode districts around Accrington, Barnoldswick, Blackburn, Burnley, Clitheroe, Colne, Darwen, Nelson and Rossendale in England.
TN postcode area
The TN postcode area, also known as the Tonbridge postcode area, is a group of 40 postcode districts in England, which are subdivisions of 24 post towns.
 These postcode districts cover an extensive area from the Greater London border at Westerham to the Sussex coast, including south Kent (including Tunbridge Wells, Tonbridge, Ashford, Sevenoaks, Cranbrook, Edenbridge, New Romney, Romney Marsh and Tenterden) and northern and eastern East Sussex (including Hastings, Battle, Bexhill-on-Sea, Crowborough, Etchingham, Hartfield, Heathfield, Mayfield, Robertsbridge, Rye, St Leonards-on-Sea, Uckfield, Wadhurst and Winchelsea).
 Additionally, small parts of TN14 and TN16 cover the rural southern part of the London Borough of Bromley, while TN16 also includes the village of Tatsfield which, although in the county of Surrey, has a Kent postal address.
 All post in the TN postcode area is sorted at the Royal Mail Sorting Office in Rochester which also sorts all mail from the adjoining ME (Medway) postcode area.
Burnley
Burnley ( ) is a market town in Lancashire, England, with a population of 73,021.
 It is 21 mi north of Manchester and 20 mi east of Preston, at the confluence of the River Calder and River Brun.
LA postcode area
The LA postcode area, also known as the Lancaster postcode area, is a group of postcode districts across north Lancashire, south Cumbria and parts of North Yorkshire.
 It includes Ambleside, Askam-in-Furness, Barrow-in-Furness, Broughton-in-Furness, Carnforth, Coniston, Dalton-in-Furness, Grange-over-Sands, Kendal, Kirkby-in-Furness, Lancaster, Millom, Milnthorpe, Morecambe, Sedbergh, Ulverston and Windermere in England.
 Despite being named after Lancaster, Lancashire, the largest settlement within the limits of the LA postcode area is Barrow-in-Furness, Cumbria.
TS postcode area
The TS postcode area, also known as the Cleveland postcode area, (or unofficially as the "Teesside postcode area") comprises the postcode districts covering the post towns of Billingham, Guisborough, Hartlepool, Middlesbrough, Redcar, Saltburn-by-the-Sea, Stockton-on-Tees, Trimdon Station, Wingate and Yarm in north east England.
 The postcode is centred on the town of Middlesbrough, with the TS1 postcode given to Central Middlesbrough and the residential areas immediately surrounding the town centre.
PE postcode area
The PE postcode area, also known as the Peterborough postcode area, is a group of postcode districts covering a large area in eastern England, including Peterborough, Huntingdon and St. Neots in Cambridgeshire, King's Lynn in Norfolk and Boston and Stamford in Lincolnshire.
 Parts of East Northamptonshire also have the postcode instead of the NN postcode, as does a very small part of Bedfordshire.
 Her Majesty the Queen's private house at Sandringham in north-west Norfolk has a PE postcode.
E postcode area
The E (Eastern) postcode area, also known as the London E postcode area, is the part of the London post town covering much of the eastern part of Greater London, England and also Sewardstone in Essex.
 Since the closure of the East London mail centre during the summer of 2012, inward mail for the E postcode area is now sorted at Romford Mail Centre, with the IG and RM postcode area mail.

Answer: Burnley