Southeast Asia Treaty Organization or SEATO is made up of eight states from Southeast Asia, Europe, America, etc. in order to set up defenses in their countries. The treaty was signed in Manila, Philippines in 1954. The eight states include New Zealand, Australia, Bangladesh, Thailand, Philippines, United Kingdom, France, and United States. Therefore, among the choices, (a) China is not included in the said treaty. However, the treaty does not only extend to these states. It includes other countries under its protection but these countries preferred not to join the organization for some reasons.