The source-backed, question-specific record explains: The Company victory at Buxar over Mir Qasim, Shuja-ud-Daula and Shah Alam II was followed by the Treaty of Allahabad arrangements in 1765. These placed the Mughal emperor under Company influence, reshaped Awadh’s position and preceded the imperial grant of Diwani rights in Bengal, Bihar and Orissa. Buxar therefore produced a stronger military and political settlement than a vague claim of supremacy over one region alone. This evidence establishes the historical relationship required in this Important Battles item. Option A gives The Treaty of Allahabad arrangements of 1765 and satisfies every condition stated in the question. The remaining choices—The Treaty of Mangalore, The Treaty of Salbai and The Treaty of Seringapatam—do not satisfy the complete requirement. The reliable checking method is to identify the named battle first, recall or verify its verified participant or outcome, and then read qualifiers such as “both works,” “original language,” “first published,” “correctly matched” or “incorrectly matched.” These qualifiers determine what counts as the answer. Replaying that method for this Important Battles question confirms The Treaty of Allahabad arrangements of 1765 without relying on option position.