From the molecular formula and spectroscopic data provided, please calculate the degree of unsaturation and propose a structure for the following compounds. Include what absorbance(s) in the IR were used in the determination and an analysis of the NMR. The integration of the NMR signals is provided along with the multiplicity (s= singlet, d= doublet, t= triplet, q= quartet, sx= sextet, sp= septet, m= multiplet). 5. C4H8O2