How long did they hike with full backpacks along the truck each day?

• A. 10 days.
• B. 5 days.
• C. 20 days.
• D. 30 days.

Answer: (A)

The main idea here is to identify the time span given for a repeated daily activity in the passage. The text describes the daily hike with full backpacks along the truck as lasting for ten days. That specific duration is what answers the question—the hike happened across a ten-day period, with the activity occurring each day within that timeframe.

The other numbers don’t fit because they would change the overall length of the described period, which isn’t supported by the information given. When you’re faced with similar questions, look for any phrase that ties the activity to a time period (for example, “for X days” or “over X days”) and use that exact duration as your answer.