Which of the following places in Assam is famous for its Oil refinery?

The correct answer is option 3) i.e. Bongaigaon . Bongaigaon Refinery (BGR) is the 8th refinery of IndianOil. Consequent upon the amalgamation of Bongaigaon Refinery & Petrochemicals Limited (BRPL) with IndianOil on 25th March 2009, it became the eighth largest refinery of IndianOil and came to be known as IndianOil, Bongaigaon Refinery. The refinery has a uniqueness of its own with an existence of over 45 long years, Bongaigaon Refinery have been serving the energy needs of the state along with the rest of the nation. Situated amidst its spectacular beauty in the Chirang district of Assam, it is about 200 km west from the state capital Guwahati. The Digboi Refinery was set up at Digboi in 1901 by Assam Oil Company Ltd. The Indian Oil Corporation Ltd (IOC) took over the refinery and marketing management of Assam Oil Company Ltd. with effect from 1981 and created a separate division.