Q: A biofilm is a colony of prokaryotes that is stuck to what?


Read this paragraph and choose the correct option from the provided answers:

Some prokaryotes form structures consisting of many individual cells, like the cells in Figure below . This is called a biofilm. A biofilm is a colony of prokaryotes that is stuck to a surface. The surface might be a rock or a host's tissues. The sticky plaque that collects on your teeth between brushings is a biofilm. It consists of millions of prokaryotic cells.

 Choices:

- the middle

- the bottom

- skin

- surface


A:
surface