Task: Question Answering
Input (English): Question: The degenerative neurological disorder that occurs as a result of degeneration and loss of nigrostriatal dopaminergic neurons is called: 
 Options:  <1> Phenylketonuria <2> Transmissible spongiform encephalopathy or TSE. <3> Multiple sclerosis. <4> Huntington's disease <5> Parkinson's disease
Output (English): 5