Question

1. what is the purpose of evidence in an argumentative essay?

it gives another opinion about the claim.
it backs up the claim.
it backs up the counter - claim.
it provides an additional claim.

Explanation:

In an argumentative essay, the core claim is the writer's main position. Evidence (like facts, data, or expert testimony) serves to validate and support this central claim, not to add opinions, support counter-claims as its primary purpose, or introduce new claims.

Answer:

It backs up the claim.