Answer:
 I would have to say c I have learned this type of stuff in the past
 
        
             
        
        
        
Answer:
<em>The correct option is d)  an ecotone</em>
Explanation:
An ecotone can be described as an area of transition between two different biomes. An estuary can be described as an ecotone where the river water meets the seawater. The freshwater biome mixes with the seawater biome in an estuary. Unique plants and animals are grown in an estuary which are adapted to live in such an environment. The water present in an estuary is termed as brackish water. Hence, the correct option is d. 
 
        
                    
             
        
        
        
Meiosis a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
 
        
             
        
        
        
<span>The Answer is D. Maintaining Structure</span>