Design your entity$-$relationship diagram $($ERD$)$ for the classes based on your understanding of complex entity relationships, including one$-$to$-$one, one$-$to$-$many, and many$-$to$-$many relationships. $$ The web application should store the information of every class and relationship using forms. For example, the Person class may have properties such as ID$,$ Name, DOB, etc. $$ Use appropriate data annotation and input validations for the HTML elements in the MVC forms. You can either use custom or default error messages.