Final answer:
The option that best illustrates brain plasticity after Genna's operation is her showing some improvement in language and motor skills. This indicates neuroplasticity which allows the brain to form new connections and adapt after injury or surgery.
Step-by-step explanation:
The observation that best illustrates the brain's plasticity following Genna's surgery to remove nearly the entire right hemisphere of her brain is C) Genna showed some improvement in language and motor skills. This indicates that despite the significant loss of neural tissue, the remaining parts of the brain have begun to adapt and compensate for the lost functions. In contrast, options A and D suggest a lack of plasticity and option B does not necessarily reflect an improvement attributable to plasticity.
Neuroplasticity enables the brain to reorganize itself by forming new neural connections throughout life. It can occur due to personal experiences, developmental processes, or in response to damage or injury. Thus, in Genna's case, even though she underwent drastic surgery, neuroplasticity allows her brain to recover some functions and potentially develop new pathways to regain or improve certain abilities over time.