PSSC is a brokerage firm that buys and sells stocks for its clients. Thus, the main actors are broker and clients. PSSC has offices in different cities and each broker works in only one of these offices. A broker can also be an office manager (For the office he/she works in).Clients own accounts, and any account can have more than one owner like joint account. Each account is also managed by at most one broker. A client can have several accounts and a broker can manage several accounts, but a client cannot have more than one account in one office. Given these conditions, design an ER diagram for this application using CHENs notation, no other notation is acceptable and will not be graded. Write any unspecified requirements and any assumptions that you need to make the specification complete. In your ER diagram; a. Identify each entity type and relationship type. b. Identify attributes and key attributes for each entity type and/or relationship type. c. Identify all of the structural constraints. ER diagram required using CHEN'S notation with list of assumptions made.