Your <span>epithelial (skin).</span>
        
             
        
        
        
Answer:
The correct option is A. they evolved from land mammals.
Explanation:
Evolution can be described as a process through which organisms in a species change over a period of time due to the natural selection of the environment. Those organisms that have many similarities in their functions or structures are considered closer to one another and have the same common ancestors.
The properties mentioned in the question about cetaceans resembles the properties of land mammals. For example, cetaceans lack gills and breathe air. Land mammals also do not have gills and need to respire for living. The cetaceans have fin bones which are similar to the limb bones in the land mammals. Hence, these observations show that cetaceas have evolved from land mammals.
 
        
             
        
        
        
Science definitions for producer. An autotrophic organism that serves as a source of food for other organisms in a food chain. Producers include green plants, which produce food through photosynthesis, and certain bacteria that are capable of converting inorganic substances into food through chemosynthesis. 
 
        
             
        
        
        
Because the mother had red her it means the woman is heterozygous and the man is homozygous recessive so there is a 50% chance of having a child with red hair and a 50% chance of having a child with black hair.
        
                    
             
        
        
        
I believe the answer you are looking for is a cell cavity. Also known as: Cavity of cell, or cell space