The correct answer is Only statement A is true. CONCEPT: The process of separating constituents of petroleum is known as refining. Sulphuric acid is the major chemical used for petroleum refining. According to Arrehenius theory acids are the compounds which dissociate to form hydrogen(H+ )ions in the solution and bases are the compounds which dissociate to form hydroxide(OH-) ions in the solution. EXPLANATION: H2S04 is used in the refining of petroleum to remove sulphur and other compounds. Sulphuric acid treating results in partial or complete removal of unsaturated hydrocarbons, sulphur, oxygen and nitrogen compounds. It is used to improve the odour, colour and stability and some other properties. It is also used in the manufacture of chemical, plastic, paint, drugs, synthetic fibre, etc. Sodium hydroxide is a strong base with components Na+ and OH-. The basic nature of Sodium Hydroxide (NaOH) is due to the presence of negative hydroxide (OH-) ions in the solution.