The Phrase "Pruning" Is Used to Describe the Development of the Nervous

The phrase "pruning" is used to describe the development of the nervous system. The author contrasts this with marble sculpture. What do these analogies represent?

A) They relate to the loss of neurons early in development.
B) They relate to the loss of axons that do not receive trophic support.
C) They relate to growth cone growth and retraction during chemotaxis.
D) All of the above are true.