Question

how did us president warren harding step away from the league of nations?
he demanded many new rules and regulations.
he declared an end to us membership in the league of nations.
he said the us would play a limited role in the league of nations.
he announced his support for an isolationist policy.

Explanation:

Warren Harding declared an end to US membership in the League of Nations. The League of Nations was an international organization established after World War I. The US, under Harding, decided not to be part of it. Demanding new rules (if not leading to withdrawal) wouldn't be a way to "step away". Saying a limited role still implies some form of membership. Announcing support for isolationist policy is a general stance but not the direct action of stepping away from the League. The most direct action of stepping away is declaring an end to membership.

Answer:

He declared an end to US membership in the League of Nations.