For example, ________ the 1840s, thousands of people died in the USA looking for gold.

For example, ________ the 1840s, thousands of people died in the USA looking for gold.

• A. In
• B. During
• C. On
• D. At

Answer: (A)

Prepositions of time with decades. When you’re naming a broad time period like a decade, the natural choice is to use in: in the 1840s. This treats the decades as a general time frame in which those events occurred. The sentence is about events that happened over that whole period, not at a single moment, so in fits smoothly. On the other options, for a time span of years or a decade we don’t use on or at. On is for specific dates or days (on July 4), and at is for a particular point in time (at noon). During could work to emphasize the duration (during the 1840s), but in is the more typical, neutral way to introduce a historical period here.

Prepositions of time with decades. When you’re naming a broad time period like a decade, the natural choice is to use in: in the 1840s. This treats the decades as a general time frame in which those events occurred. The sentence is about events that happened over that whole period, not at a single moment, so in fits smoothly.

On the other options, for a time span of years or a decade we don’t use on or at. On is for specific dates or days (on July 4), and at is for a particular point in time (at noon). During could work to emphasize the duration (during the 1840s), but in is the more typical, neutral way to introduce a historical period here.