Answer:
The heterotrophic protists would since they use them to gather food.
Step-by-step explanation:
The most appropriate of the options is heterotrophic protists because these are the protists such as paramecium which are not able to prepare their food themselves. Therefore, they need to use cilia to make a current that brings food sources near their oral groove that makes a connection with cytopharynx. The cytopharynx is a structure that helps in the ingestion of food into the mouth like part called cytostome . This serves as an opening point for the food entrance.
Food upon entering into the cytosome moves to get into the food vacuole where efficient enzymes for the breakdown of food are present. The smaller food components are used by protists as nutrient and ultimately energy source.
The waste product or undigested food are removed from the body of paramecium through structure similar to anus called cytopyge.
Please see attached image of paramecium for better insight.
Hope it help!