Software Architecture and Design Patterns (a) Is it good to have a loosely-coupled system? Explain your answer. [4 marks]< (b) What are design patterns? [2 marks]< ( (c) What are the main cost and benefit of using design patterns? [4 marks]< (d) Describe the architectural styles of client/server and three-tier. Explain the main benefit of using the three-tier architecture in place of the client/server architecture. [5 marks]