This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
A 39 years old male patient presents with waxy flexibility, negativism and rigidity. Most probable diagnosis is? 
Select and explain. 
A. Excitatory catatonia, B. Stuporous catatonia, C. Paranoid schizophrenia, D. None
B: Stuporous catatonia
Answer: B: Stuporous catatonia 
Explanation: Ans. B. Stuporous catatonia Stuporous (retarded) catatonia : Characterized by extreme retardation of psychomotor function, which includes mutism, rigidity, negativism, posturing, echolalia, Echopraxia, Catalepsy (waxy flexibility), ambitendency, gegenhalten, streotypies, stupor, Mannerism, Grimicing, Automatic obedience, and verbigeration.