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

Which of the following definitions best describes 'shield'?

A. In geology, a the concept is a land mass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a the concept today.
B. A the concept is an area on Earth where two tectonic plates move towards one another and subduction occurs. [Wikipedia]
C. The extensive central cratons of continents may consist of both shields and platforms, and the crystalline basement. A platform is that part of the craton for which the basement is overlain by horizontal or subhorizontal sediments. [Wikipedia]
D. 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]

Answer: 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]