Create a complete ERD in Crow$$s Foot notation and make sure to use hierarchy.

Case Study

You've been hired by a multinational corporation operating in the pharmaceutical industry. The corporation conducts extensive research and development $($R&D$)$ activities across various therapeutic areas. As part of your role, you're tasked with designing a comprehensive database system to manage the company's research projects, which span multiple departments and involve collaboration with external partners such as academic institutions and contract research organizations $($CROs$).$ The database must capture detailed information about each research project, including its title, start date, end date, budget allocation, and primary investigator. Moreover, the corporation's R&D activities are organized into specialized divisions, each focusing on distinct therapeutic areas such as oncology, neurology, cardiology, and immunology. Each division may further specialize in specific subcategories within their respective therapeutic areas

B$.$ Explain how multiple levels of specialization can be incorporated into the ERD design to represent the hierarchical structure of the corporation's R&D divisions and therapeutic areas.

C$.$ Explain, with a diagram the purpose of using a subtype discriminator. Give a scenario where omitting a subtype decimator can result in data anomalies