In Paramecium, food is ingested through

The correct answer is cytosome.

Paramecium is a unicellular, ciliated organism. It has a specialized structure for food ingestion called the cytostome (also commonly referred to as the cytosome or cell mouth).
During feeding, the beating of the cilia lines the oral groove, sweeping food particles (such as bacteria and small algae) down toward this cell mouth.
From the cytosome, the food is directed into the cytopharynx (cell gullet), where it is packaged into food vacuoles for digestion.
Meanwhile, cytoproct and cytopyge refer to the cell anus used for the excretion of undigested waste. Therefore, the cytosome is the specific site where ingestion occurs.