The Notion of Structural Plasticity

The notion of structural plasticity:

A) has been demonstrated in animal studies but there is no evidence for structural plasticity in humans.
B) is the idea that learning, active practice, or environmental stimulation can cause physical changes in the brain's structure.
C) led to the idea of surgically cutting the corpus callosum as a possible treatment for severe cases of epilepsy.
D) is the idea that the brain has the ability to shift functions from damaged to undamaged brain areas.