just b and d

C.58 Propose a structure consistent with each set of spectral data: a. C4H8Br2 : IR peak at 30002850cm1; NMR (ppm): 1.87 (singlet, 6 H) 3.86 (singlet, 2 H) b. C3H6Br2: IR peak at 30002850cm1; NMR (ppm): 2.4 (quintet) 3.5 (triplet) c. C5H10O2 :IR peak at 1740cm1; NMR (ppm): 1.15 (triplet, 3 H) 2.30 (quartet, 2 H) 1.25 (triplet, 3 H) 4.72 (quartet, 2 H) d. C3H6O: IR peak at 1730cm1; NMR (ppm): 1.11 (triplet) 2.46 (multiplet) 9.79 (triplet)