The correct answer is option 2, Fungi.

Yeast is a single-celled organism and belongs to the kingdom Fungi. Fungi are a diverse group of organisms that include molds, mushrooms, and yeasts. They are characterized by their ability to obtain nutrients from organic matter in their environment. Yeasts, like other fungi, are eukaryotic, which means they have a defined nucleus and other membrane-bound organelles.

Yeast is commonly used in baking to make bread because of its ability to ferment carbohydrates. During fermentation, yeast breaks down the sugars in the bread dough, producing carbon dioxide gas and alcohol. The carbon dioxide gas creates bubbles, causing the bread dough to rise. The alcohol is evaporated during the baking process. This fermentation process gives bread its fluffy texture and distinctive taste.

It is important to note that yeast is not a member of the Protista, Monera, or Protozoa groups. Protista is a group that includes diverse organisms such as algae and protozoans. Monera, which is an outdated term, used to refer to prokaryotic organisms like bacteria. Protozoa refers to a specific group of single-celled organisms that are classified under Protista. Therefore, the correct classification for yeast