Solution
We need to find the main purpose - what's the author really trying to do here? Let us trace the logic step by step.
The passage opens with "Despite their fierce reputation, Vikings may not have always been the plunderers and pillagers popular culture imagines them to be." This immediately signals the author wants to challenge how we think about Vikings.
Then it provides evidence -> reindeer antler combs found in Danish marketplaces -> these came from Norway -> Vikings must have been trading before they were raiding.
From passage: "Since the artifacts were found in marketplace areas at each site it's more likely that the Norsemen came to trade rather than pillage. Most of the artifacts also date to the 780s, but some are as old as 725. That predates the beginning of Viking raids on Great Britain by about 70 years."
The logic flow: Popular image says Vikings = raiders -> But archaeological evidence shows -> They were traders first -> This challenges the popular perception.
🟠Option 1 -> scope-error -> focuses only on explaining the combs, but the combs are just evidence for a bigger point about challenging Viking perception
🔴 Option 2 -> context-shift -> the passage mentions dates but isn't trying to change official Viking Age dates - it's using those dates to show trade came before raiding
🟠Option 4 -> degree-error -> says Vikings were both raiders and traders, but the passage argues they were traders first, before becoming raiders
🟢 Option 3 is correct -> captures both the challenge to popular perception and the use of archaeological evidence perfectly
The key insight: Don't get distracted by the specific evidence (combs, dates). Focus on the bigger argument the author is making with that evidence.