comparing and contrasting 4 different DBMS systems

The DBMS to compare:

Note: You MUST make a recommendation at the end of the paper and justify your recommendation

There are no wrong answers. This is about your thoughts and research

I am the owner of a small start up company that has an idea for a new product. There are other products out there that do this but we think our solution is better and will sell. Our investors feel the same way. We already have some potential buyers based on our prototypes.
Our product is a web based application for managing school cafeterias.
The application can work at individual schools and can be licensed by individual schools or a district and utilized by all schools in the district because it is web based.
We are the creators of the application and will maintain it in the “Cloud”. Our customers will not need to worry about buying, maintaining, or interfacing directly with the database because it is hidden from them behind our application.
You are picking the DBMS, not a separate application. That is what we are building and we need something to manage all the data involved.

With your choice of DBMS & application (you don't need to pick application), you will need to:

Other Considerations

You do not need to design this database
You only need to make an intelligent DBMS recommendation based on the application described and the potential customers.
You do not need to worry about developer knowledge or expertise.

Grading

Each database review will be evaluated based on thoughtfulness and listing of features, benefits, and shortcomings.

Final conclusion and recommendations will be worth 4 points. A comparison grid of features considered should be part of this conclusion.

Your final recommendation and reasoning will be evaluated as part of this extra credit assignment.

Expectation from Instructor

I am expecting an explanation of what each database is.
For example, is it relational? What advantages and disadvantages does each database have in relationship to the others?
And, Yes this would be an explanation of the features of that particular database. Does one database have features unique to it that would be an advantage over the others for this particular problem? If it does, is that feature or features enough for you to recommend its usage over the others?
What are the factors that you are using to recommend this particular database over the others?
I want you to explain why you think these factors are important in the context of the problem. I want you to relate these factors to specific features of a specific DBMS that you recommend.
Ultimately, I am looking for some thoughtful consideration to the problem presented and how it should be solved. I am interested in your research as to the features of each DBMS and how they may differ from one another. What sets them apart? I am interested in the journey you take and your discoveries more than the final outcome. That is why I state there is no wrong answer to your recommendation. I want you to apply some of what you learned in this course.