Explanation
In this vocabulary item, Ardent is the closest synonym of Fervent, so option A is correct. The word Fervent and the word Ardent share the same central sense in the context tested by the question, although usage, tone and grammatical form should still be checked before substituting one for the other. A synonym is not required to be identical in every possible sentence; it must preserve the intended meaning in the relevant context. Here, replacing Fervent with Ardent keeps the core idea intact without reversing the tone or changing the action, quality or state expressed by the target word. The alternatives Shorten, Crumble and Twist do not express the same central meaning as Fervent. This distinction matters because competitive examinations often place one accurate synonym beside three familiar but contextually unsuitable words. To verify Fervent independently, identify its part of speech, state a short definition, and place both Fervent and Ardent in the same simple sentence. If the sentence retains its essential meaning and grammatical structure, the synonym relationship is supported. Learners should revise Fervent together with Ardent, a brief usage cue and the contrasting distractors.