Region in the body where polio virus multiplies is

The correct option is Intestinal cells.

Polio, or poliomyelitis, is a highly infectious viral disease caused by the poliovirus. The transmission and replication of the poliovirus inside the human body follow a specific pathway:
1. Entry into the body: The virus enters the body through the mouth, typically via the fecal-oral route (ingestion of contaminated water or food).
2. Primary replication: Upon entering the pharynx and gastrointestinal tract, the virus infects the mucosal cells. The primary site where the poliovirus actively multiplies is in the lymphoid tissues of the throat and the intestinal cells (specifically in the Peyer's patches of the intestine).
3. Spread: From the intestinal cells, the virus is excreted in feces and can also enter the bloodstream (viremia). It is only in a small percentage of cases that the virus crosses into the central nervous system to infect and destroy nerve cells (motor neurons), leading to paralysis.

Therefore, the primary region in the body where the poliovirus multiplies and resides before potentially spreading to other tissues is the intestinal cells.