What is the basic feature of the "ASEAN Way"?

The correct answer is Option 3 - A form of interaction that is informal, non confrontationist and cooperative.

Unlike the EU there is little desire in ASEAN for supranational structures and institutions. ASEAN countries have celebrated what has become known as the ‘ASEAN Way’, a form of interaction that is informal, nonconfrontationist and cooperative. The respect for national sovereignty is critical to the functioning of ASEAN.