Assertion: The formation of CIS came as a surprise to other Republics, especially to the European ones.

Reason: The issue of exclusion of the Central Asian republics was solved by making them the founding members of the CIS.

The Assertion is incorrect but the Reason is correct.

The declaration on the disintegration of the USSR and the formation of the Commonwealth of Independent States (CIS) came as a surprise to the other republics, especially to the Central Asian ones. The exclusion of these republics was an issue that was quickly solved by making them founding members of the CIS.