Parkinson's disease is caused by the degeneration of neurons in which part of the brain?

The sympathetic nervous system stimulates $.............$.

Statement $I :-$ The cerebral medulla is referred to as the grey matter due to its greyish appearance.
Statement $II :-$ The neuron cell bodies are concentrated in cerebral medulla giving the colour.

In which of the following is the cerebral cortex absent?

The inner part of the cerebral cortex is referred to as:

Cerebrospinal fluid is present