2 a. The composition of Computer Networks and Communication is said to be divided into layers for effective communication. Give reason(s) for this approach. (7 marks) b. With appropriate illustrations discuss the structure of the Internet. (5 marks) c. Differentiate between an Isotropic Antenna and Parabolic Reflective Antenna. Illustrate with Diagram where applicable. (4 marks) d. Discuss Wireless radio propagation by ground wave, Sky wave and Line of sight (illustrate with diagrams). (7 marks) e. Explain the electromagnetic Isolation advantage of fiber Optics cable over other forms of guided medium (7 marks)