Be sure to answer all parts. Identify the structures of isomers A and B (molecular formula C9H10O). Compound A: IR peak at 1742 cm−1; 1H NMR data (ppm) at 2.15 (singlet, 3 H), 3.70 (singlet, 2 H), and 7.2−7.4 (multiplet, 5 H). Compound B: IR peak at 1688 cm−1; 1H NMR data (ppm) at 1.22 (triplet, 3 H), 2.98 (quartet, 2 H), and 7.28−7.95 (multiplet, 5 H). Compound A: draw structure ... Compound B: draw structure ...