By signing which declaration did ASEAN come into emergence?

Bangkok declaration.

The correct answer is Option 1 - Bangkok declaration.

ASEAN was established in 1967 by five countries of this region — Indonesia, Malaysia, the Philippines, Singapore and Thailand — by signing the Bangkok Declaration.  Over the years, Brunei Darussalam, Vietnam, Lao PDR, Myanmar (Burma) and Cambodia joined ASEAN taking its strength to ten.