Find out the correct meaning of the underlined idiom in the given sentence:
"It is unfortunate that India has mostly been at loggerheads with all her neighbours."

The correct answer is Option D (Disagreeing or quarreling with).

Key Points:
• Idiom Analysis: The phrase 'at loggerheads' is a popular English idiom used to describe a state of severe dispute, persistent disagreement, or strong conflict between two parties.
• Detailed Option Analysis:
• Option 1 (To be on good terms): This is the exact antonym of 'at loggerheads'. Being on good terms implies friendly relations.
• Option 2 (To invite): Irrelevant contextually and grammatically to the idiom.
• Option 3 (Doing business only): Commercial engagement is not implied by this idiom.
• Option 4 (Disagreeing or quarreling with): Correct. It accurately conveys the condition of being in conflict or dispute with neighbor nations.
• MPSC Exam Insight: 'At loggerheads' is frequently tested alongside idioms like 'at daggers drawn' (hostile/inimical) and 'at variance' (in disagreement).
• Key Takeaway: Remember: 'At loggerheads' means involved in a strong disagreement or conflict with someone.