Consider the case study below and answer the questions which follow. A large law firm wants to construct a database to record all the information about the activities of the company. Part of the company's activities are described below. The staff of the company consists only of a number of lawyers and a number of legal assistants. The number of staff is small enough that they can be identified by their name. Each staff member has a rate (\$ per hour) and number of years of experience (computed from the date they have joined the company). The lawyers each have a speciality like company law, criminal law. It is important to store all the qualifications of the legal assistants. The primary activity of the company is legal cases for clients. Each active case is identified by a CaseID number, and involves a particular client. At least one lawyer, and possibly more, will work on each case, and each lawyer may work on several cases (or on none). Every day, they record how much time they have worked on each case. There are several different courts in the country. They are identified by a court name. Their level (magistrate, superior, appeal) and their district also need to be stored. The court rooms where trials take place are identified by which court they belong to and a courtroom number (1,2,3, etc). Each court room also has an address. Each case will be tried by one court, though each court may be trying many cases, and the company may or may not have cases with all the different courts. There cannot be any case which is not tried by any court or which is not worked on by any lawyer. a) Draw an Entity Relationship (ER) Diagram for the law firm database, as described above, secifying all constraints and cardinalities