Using the kerberos version 4 (lecture notes 4 - authentication applications: slide 21) answer the following questions (a) explain what is kc and how it is generated or where it is stored; (b) explain what is kc, tgs and how it is generated or where it is stored; (c) explain what is the purpose of the tickettgs and what it contains; (d) explain what is the purpose of the ticket, and what it contains; note: for tickets, list of the values is not considered a complete answer. you must also explain what each item represents.