Task: Class Definition Understanding (ontology: Earth_Environment/SWEET)

Which of the following definitions best describes 'active continent'?

A. A distinction of whether the continental margins are active (subducting). [Wikipedia]
B. The extensive central cratons of continents may consist of both shields and platforms, and the crystalline basement. A the concept is that part of a craton in which the usually Precambrian basement rocks crop out extensively at the surface. [Wikipedia]
C. A the concept is an old and stable part of the continental crust that has survived the merging and splitting of continents and supercontinents for at least 500 million years. Some are over two billion years old. Cratons are generally found in the interiors of continents and are characteristically composed of ancient crystalline basement crust of lightweight felsic igneous rock such as granite. They have a thick crust and deep roots that extend into the mantle beneath to depths of 200 km. [Wikipedia]
D. A distinction of whether the continental is on a stable paltform, i.e., over millions of years. [Wikipedia]

Answer: A distinction of whether the continental margins are active (subducting). [Wikipedia]