(a) Explain the three service models of cloud computing, namely Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), and Software-as-a-Service (SaaS). Give an example for each service model. [3 marks] (b) Discuss the limitations of mobile computing, compared to mobile cloud computing. Also discuss how mobile cloud computing can help to overcome these limitations. [3 marks] (c) When the energy efficiency in cloud is concerned, discuss why the power consumption is critical to the cloud data center. Discuss how we constitute the dynamic voltage- frequency scaling (DVFS) technique. [2 marks] (d) Discuss the advantage and disadvantage of implementing the cloud platforms on the High Performance Computing (HPC) industry. [2 marks]