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

Which of the following definitions best describes 'geological boundary'?

A. the concept is an 'earth material' that is consituted by an aggregate of solid particles but is not consolidated into a 'rock' it self.
B. An the concept is a solid consolidated 'earth material' that is 'constituted by' an aggregate of particles made of mineral matter or material of biological origin.
C. It is a fiat surface that is 'located in' the external surface of a 'geological object'.
D. It is a 'relational quality' that 'inheres in' two distinct 'geological object' that are 'externally connected with'

Answer: It is a fiat surface that is 'located in' the external surface of a 'geological object'.