Option 1: Iran is not a member of the Gulf Cooperation Council (GCC). Iran is not located on the Arabian Peninsula and has a different political and religious system from the other members of the GCC. Additionally, Iran has historical and ongoing conflicts with some of the GCC members, such as Saudi Arabia and the United Arab Emirates.
Option 2: Saudi Arabia is a founding member of the GCC, along with Kuwait, Bahrain, Qatar, Oman, and the United Arab Emirates. It is also the largest and most influential member of the organization, playing a leading role in regional politics and economics.
Option 3: Oman is a member of the GCC, having joined the organization in 1981, a year after its establishment. Oman shares borders with several GCC members and has strong economic and cultural ties with the other members.
Option 4: Kuwait is a founding member of the GCC and has been an active participant in the organization`s activities since its establishment. Kuwait has close economic ties with other GCC members and has cooperated with them on various regional issues.
In conclusion, the option that is not a member of the Gulf Cooperation Council is Option 1: Iran. The other options - Saudi Arabia, Oman, and Kuwait - are all members of the GCC.