Final answer:
Indonesia is not one of the primary Pacific island groups, which are Micronesia, Melanesia, and Polynesia. Indonesia is part of Southeast Asia. The correct option is D.
Step-by-step explanation:
The correct answer to the question of which of the following is not one of the Pacific island groups is D. Indonesia. The Pacific island groups can be primarily categorized into three regions: Micronesia, Melanesia, and Polynesia. These regions are characteristically distinct in terms of their physical geography, the local inhabitants, and their locations.
Melanesia includes islands from Papua New Guinea to Fiji, while Micronesia encompasses small islands located north of Melanesia, composed mainly of low islands that are typically coral and low in elevation. Polynesia, conversely, includes many high islands that are volcanic in origin and mountainous, such as the Hawaiian Islands.
Indonesia is not classified within these Pacific island groups as it is considered part of Southeast Asia and does not fall into the geographical categorization of Micronesia, Melanesia, or Polynesia, despite some of its islands sharing characteristics with these Pacific island regions.