Choose the correct option. The Eiffel Tower is one of _______ towers in the world.

The correct answer is "the most famous". Here's why: * We use "the most" to form the superlative degree of an adjective. Superlative adjectives are used to describe something at the highest or lowest degree of a quality (the best, the worst, the most beautiful, etc.). * In this case, we're saying the Eiffel Tower is the most famous of all the towers in the world, which makes it superlative. So, the complete sentence is: The Eiffel Tower is one of the most famous towers in the world.