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

Which of the following definitions best describes 'tectonic movement'?

A. A the concept is a process during which lava, tephra (ash, lapilli, volcanic bombs and blocks), and assorted gases are expelled from a volcanic vent or fissure.
B. A material transport process which arises spontaneously due to physical heterogeneities in a portion of a material and forces which act throughout its volume.
C. A process during which pieces of a planetary crust and uppermost mantle move towards one another.
D. A process during which pieces of a planetary crust and uppermost mantle move.

Answer: A process during which pieces of a planetary crust and uppermost mantle move.