please help and answer all parts for isomer B

The following IR spectra were taken on two isomeric esters with molecular formula C5H6O2. Which are they? Assign recognizable IR absorptions, labeling clearly what they are (e.g. sp3CH stretch), then provide a short explanation (only keywords, or a few sentences) describing your reasoning on why you chose those structures: Isomer A; assign four IR-absorption bands. Note that the band at 2250cm1 is unusually strong, due to the polar nature of the substituent on that bond. Structure: Brief reasoning on how you deduced this structure from the available data