Compare between mountain and island

An island is a piece of land surrounded by water. A Plateau is a raised piece of land above the plains or the sea. The Indian ‘Deccan’ is a central plateau ranging from 100 metres to 1000 metres above sea level.

mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. A mountain differs from a plateau in having a limited summit area, and is larger than a hill, typically rising at least 300 metres (1000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges.

answer; i believe the correct answer is (a) the correlation between the cause variable and outcome variable is zero;