Explanation
In this vocabulary item, Obtain is the closest synonym of Derive, so option D is correct. The word Derive and the word Obtain 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 Derive with Obtain keeps the core idea intact without reversing the tone or changing the action, quality or state expressed by the target word. The alternatives Clear, Precise and Understand do not express the same central meaning as Derive. This distinction matters because competitive examinations often place one accurate synonym beside three familiar but contextually unsuitable words. To verify Derive independently, identify its part of speech, state a short definition, and place both Derive and Obtain in the same simple sentence. If the sentence retains its essential meaning and grammatical structure, the synonym relationship is supported. Learners should revise Derive together with Obtain, a brief usage cue and the contrasting distractors. This method develops contextual vocabulary, precise option elimination and dependable recall for SSC, Banking, Railway, Defence and other competitive examinations.