The correct answer is modern forms of transportation are more convenient.
The most likely reason that Londoners no longer rely on the Thames as their main mode of transportation is that modern forms of transportation are more convenient.
London, England is a modern city and one of the most important cities in the world. Although very populated, London has modern and efficient transportation forms that are preferred than traveling the Thames River. For instance, the subway system or underground transportation in London, “The Tube” is one of the most important and cherished by the Londoners. They also have the world-famous double-decker buses and trains.
The other options of the question were, b) the river is too polluted to people to travel across, c) military personnel have blocked off parts of the river, and d) Unpredictable floods make traveling the Thames dangerous.
