Figure 1 shows the infrared (IR), proton NMR spectrum and expansion of proton NMR of compound I with molecular formula of CsH3O2. The expanded proton NMR signals have been labelled as a, b, c, d and e. The carbon-13 spectrum shows signals at 14, 60, 129, 130 and 166 ppm. You can determine the Index of hydrogen deficiency (IHD) to assist your structure determination. a) Tabulate all spectral assignments. Determine the structure of compound I and label the proton correctly. b) Calculate coupling constant, 2Jgeminal from expanded proton NMR spectrum. c c) According to the proton NMR expansion, draw tree diagram of proton e and indicate its multiplicity