More than a century ______, men fought over gold.

• A. Ago
• B. Since
• C. During
• D. Before

Answer: (A)

The time distance from now is the clue: more than a century ago accurately places the event long before now and fits with the simple past verb fought. Using ago signals a past moment relative to the present, which is exactly what this sentence needs to describe a historical fact.

Since would require a perfect tense to show something that started in the past and continues to the present, which doesn’t match the simple past here. During would imply a duration within which something happened, making the sentence feel off for the idea of a single past event. Before would need a reference time to compare to, and without that point the phrase sounds incomplete.

So more than a century ago is the natural, grammatical choice to convey when the fighting over gold occurred.