A.I. Explanation:

Correct answer: through

Explanation: The word 'through' indicates a means or method by which something is achieved, fitting grammatically as it connects the clause about effective diplomacy to the subsequent description of the network of allies. It aligns contextually with the idea that diplomacy was a method of establishing alliances.

Meaning: 'Through' means by means of or via, suggesting that effective diplomacy was the method used to create a network of allies.

Wrong options:

• fitting: 'Fitting' is an adjective that describes suitability, but it does not convey the sense of method or means required in this context.
• gauging: 'Gauging' refers to measuring or assessing, which does not fit the context of establishing alliances through diplomacy.
• properly: 'Properly' is an adverb that indicates correctness or appropriateness, but it does not convey the means by which diplomacy operates.

Correct answer: Further

Explanation: The word 'Further' serves as a discourse marker that indicates an addition to the previous point, fitting grammatically and contextually as it introduces additional information about the allies' contributions, enhancing the flow of ideas in the text.

Meaning: 'Further' means in addition or moreover, indicating that the following information builds upon what has already been stated about the allies' support.

Wrong options:

• However: 'However' introduces a contrast or exception, which does not fit the context of adding more information about the allies' contributions.
• Instead: 'Instead' suggests a replacement or alternative, which is not appropriate here as the sentence is not presenting an alternative to the previous statement.
• Alternatively: 'Alternatively' also implies a choice or option, which does not align with the intent of adding further details about the allies.