Explanation:

• It comprises five main islands: Sumatra, Java, Borneo (known as Kalimantan in Indonesia), Sulawesi, and New Guinea; two major island groups (Nusa Tenggara and the Maluku Islands) and sixty smaller island groups.
• Note: New Guinea is an island to the north of the Australian mainland, but south of the equator. Politically, the western half of the island comprises two provinces of Indonesia: Papua and West Papua. The eastern half forms the mainland of the country of Papua New Guinea (PNG).

Hence option 4th is correct.