This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
Which is used as Fungal Stain in tissue biopsy sections? 
Select and explain. 
A. PAS, B. Alizarin red, C. LPCB, D. Masson Trichrome
A: PAS
Answer: A: PAS 
Explanation: Gomori Methenamine Silver (GMS) and Periodic acid-Schiff (PAS) are the two most common stains used to look for fungi intissues and in cytology specimens in the daily practice of pathology. The presence offungus in the tissue sections provides an indisputable evidence of invasive infection Ref ganong's review of medical physiology 25e