Its B, because A is supposed to be a carbohydrate and D says lipids are inorganic but they are organic. Last C, Catalyst speeds up chemical reactions not lipids. So B is the right answer they make up part of the cell and cell membrane.
Gill are typically outgrowths of tissue or clustered strands of filaments.
Any organ (in aquatic animals) that exchanges gases and other dissolved substances between the blood and surrounding water have typically outgrowths of tissues or clustered strands of filaments called gill. In a fish, gill filaments are present.
Bacteria invades and multiplies itself and make copies of itself... which affect the immune system by destroying it to some extent
Depending on the environment the organism is living in it can adapt to better survive in its habitat. For example, creatures living underwater have gills allowing them to breathe easier, and have lights attatched to their head so they can see in the pitch blackness of the deep water.