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

Which of the following definitions best describes 'embryonic cardiovascular system'?

A. A cardiovascular system that is part of a conceptus.
B. The concentration of manganese molecular entity when measured in soil.
C. A liquid produced from the fermentation of ethanol in a process that yields its key ingredient, acetic acid.
D. Soil in which trees from an orchard grow.

Answer: A cardiovascular system that is part of a conceptus.