Final answer:
The correct completion for the sentence 'Prince Felax was one of the _ men in Russia.' is 'richest', fitting the context where wealth is the implied attribute.
Step-by-step explanation:
Prince Félix was born on 3 June 1984 in the Grand Duchess Charlotte Maternity Hospital in the Grand Duchy of Luxembourg. He is the second of the five children of Grand Duke Henri and Grand Duchess Maria Teresa, the others being: Hereditary Grand Duke Guillaume, Prince Louis, Princess Alexandra and Prince Sébastien. His godparents are Prince Jean and Catalina Mestre. He was named after his great-grandfather, Prince Felix of Bourbon-Parma.
Prince Felax was one of the richest men in Russia. The question provides a fill-in-the-blank statement where a descriptive adjective is required to complete the sentence. The correct answer is (a) Richest. While there is no direct historical or literary reference to a Prince Felax, this question seems to assess the understanding of comparative and superlative forms of adjectives in the English language. In this context, 'richest' seems to be the most fitting choice, assuming Prince Felax is known for his wealth.