Answer to this question is b
        
                    
             
        
        
        
Answer:
Filtration, Reabsorption, Secretion: The Three Steps of Urine Formation. The kidneys filter unwanted substances from the blood and produce urine to excrete them. There are three main steps of urine formation: glomerular filtration, reabsorption, and secretion.
Explanation:
 
        
                    
             
        
        
        
The overall function of the digestive system as digestion and absorption of food stuffs, and the general activities of each digestive system organ is; Ingest, digest, absorb, defecate. 
Ingestion involves placing food into the mouth, propulsion involves propelling food from one organ to the next using peristalsis. Mechanical digestion involves the physical fragmenting food into smaller particles. Chemical digestion refers to breaking down food molecules to building blocks by enzymes. Absorption is the transport of digested end products to blood or lymph; and finally Defecation which involves the elimination of indigestable material from GI tract by anus. 
        
             
        
        
        
The process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.