5. Presume these two tables: sector), accountants(license#,name,age, symbol) and companies(symbol, name, where license# and symbol are primary keys. (a) Consider the sentence: find all companies and their sectors, audited by the accountant with license number 12345 Show how to code this request in (i) SQL (ii) relational algebra (b) Give SQL code to make symbol a foreign key in accountants, referring to companies as the parent table. Assume the tables already exist at the time you are creating the foreign key constraint. Choose a suitable constraint name