Many of the low islands in Oceania are _ that surround _.
A.
geysers . . . artesian wells
B.
atolls . . . lagoons
C.
geothermal plateaus . . . ice sheets
D.
lagoons . . . geysers

A. geysers...artesian wells

Explanation:

"Oceania" spans from the eastern hemisphere to the western hemisphere. It consists of many small and large islands. Its low islands are said to have come from coral origin. Many of these are "geysers" that surround "artesian wells." The artesian well is where water flows out under the existence of a "natural pressure."

Such number of geysers is brought about by the geographical location of the country and the existence of volcanic activities. Thus, many of the islands are simply "wilderness" and "uninhabited by people."

So, this explains the answer.