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

Which of the following definitions best describes 'Base Unit'?

A. A the concept is a unit pressure commonly used in meterology. 1 mbar = 0.001 bar = 0.1 kPa = 1 hPa (hectopascal)
B. A the concept is the product of at least two base or derived units. For example, 'meter per second square' denotes a the concept defined over 'meter' (a base unit) and 'per second square' (a derived unit).
C. A the concept is a unit that is not naturally decomposed into other units.
D. A the concept is a unit pressure commonly used in oceanography because it's value is generally equivalent to depth in meters. 1 dbar = 0.1 bar = 10 kPa

Answer: A the concept is a unit that is not naturally decomposed into other units.