The correct answer for Blank (i) is A. eponyms.

Explanation
The sentence provides examples of places named after people.
- A. eponyms: An eponym is a person after whom a discovery, invention, place, or other thing is named. The examples given perfectly match this definition: Alexandria (place) is named after Alexander the Great (person), and Leopoldville (place) is named after King Leopold II (person).
- B. derivatives: A derivative is a word or a thing that is based on another source. While the city names are derived from the people's names, "eponyms" is the more specific and accurate term for this naming convention.
- C. metaphors: A metaphor is a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable. This is not the case here.
- D. tropes: A trope is a figurative or metaphorical use of a word or expression. This is too broad and does not fit the specific naming pattern.
- E. diminutives: A diminutive is a shortened form of a name, often used to express affection. This is incorrect. The names are not shortened forms.