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: Pediatrics
Best site to demonstrate capillary filling in infants – 
Select and explain. 
A. Nail bed, B. Sternum, C. Ear lobule, D. Great toe
B: Sternum
Answer: B: Sternum 
Explanation: The state of microcirculation can be assessed by capillary filling time (CFT)
Firm pressure is applied over sternum or forehead by a ball of the thumb for 5 seconds. This leads to blanching.
On removal of pressure color returns. The time taken for complete return of color is designated as capillary filling time, the normal is less than or equal to 3 sec.
Prolonged CFT is the earliest sign signifying impairment or microcirculation.