The correct answer is Option a. the world oil market is not truly a market because it is not centralized in one place.

Option a is incorrect. The world oil is absolutely a market even though it is not a centralized place.

Option b is a correct statement. Part of the potential trading gains are the organized markets (stock market to be particular).

Option c is also a correct statement. The interconnectivity of the economic activity of different firms involved huge amount.

Option d is right. As centralized market hampers operation of the firm, as day-to-day actions will be depends on the top management of the firm, the move to the decentralized market system are now being adopted in different planned economies.