Option 1: This option states that SAFTA is a step towards a South Asian customs union and common market. This means that the objective of SAFTA is to move towards creating a common market and customs union among the South Asian countries. This option is correct.

Option 2: This option states that the agreement came into effect in 2006. This means that SAFTA was implemented and began its operations in the year 2006. This option is correct.

Option 3: This option states that SAFTA is a trade liberalization regime. This means that SAFTA aims to promote and facilitate free trade among the member countries by reducing or eliminating trade barriers such as tariffs and quotas. This option is correct.

Option 4: This option states that the SAFTA agreement takes precedence over any other agreement a member country may have with states outside SAFTA. This means that if a member country of SAFTA has any other trade agreements with countries outside SAFTA, the SAFTA agreement will have priority over those agreements. However, this option is not true for SAFTA. Alert - correct answer should be: "The SAFTA agreement does not take precedence over any other agreement a member country may have with states outside SAFTA."

In conclusion, only option 4 is