The sentence Le système bancaire est _ dans ce pays ("The banking system is _ in this country") requires a word that functions as a predicate adjective after est (is). The blank must therefore be filled with an adjective.
The correct answer is corrompu, the past participle of corrompre (to corrupt), used here as an adjective meaning "corrupt." The complete sentence reads: Le système bancaire est corrompu dans ce pays ("The banking system is corrupt in this country").
The other options are incorrect because they are not adjectives:
corrompt is a conjugated verb form (third person singular present indicative of corrompre). You cannot place a conjugated verb after est in this construction.
corruption is a noun. Saying est corruption would be ungrammatical without an article.
corrompre is the infinitive form of the verb. An infinitive cannot serve as a predicate adjective after est in this context.
In French, past participles like corrompu, fatigué, surpris, and fini regularly function as adjectives after être.
