In IR, label at least one band which helped you to identify the compound.

A. 1.0 ppm (singlet), 3000-3500 cm^(-1) (broad)
B. 2.5 ppm (triplet), 1700-1800 cm^(-1) (sharp)
C. 3.8 ppm (doublet), 1200-1300 cm^(-1) (strong)
D. 4.2 ppm (multiplet), 2500-2800 cm^(-1) (medium)