This is about identifiers in a record referring to other records.
You can have many to one, one to one, many to many.
E.g., if you have two tables, Authors and Books, then a book record could have a reference to an author record. Since an author can write many books, this would be a many-to-one relationship.
        
             
        
        
        
I believe the correct answer from the choices listed above is option D. <span>When planning the structure of a spreadsheet, columns are for group items and rows are for single items. Hope this answers the question. Have a nice day.</span>
        
                    
             
        
        
        
Answer:
The body of water that is most likely to be a marine ecosystem would be an estuary.
Explanation:
An estuary is a widened, often funnel-shaped mouth of a river, where fresh river water and salt sea water are mixed and thus brackish water is created, and where tidal differences can be observed. When a river flows as a system of branches, it is called a delta.
Estuaries often have a great natural value. They typically consist of swallows and salt marshes that are very rich in invertebrates and thus have a great attraction for birds, among other things.