Which of the following pairs of compound and characteristic infrared absorption are correctly matched?

1. Apropanone, $\mathrm{CH}{}_3\mathrm{COCH}{}_3$ : strong band near $1715\mathrm{c}{\mathrm{m}}^{-1}$
2. Bethanol, $\mathrm{CH}{}_3\mathrm{CH}{}_2\mathrm{OH}$ : broad band near $3300\mathrm{c}{\mathrm{m}}^{-1}$
3. Cethanamine, $\mathrm{CH}{}_3\mathrm{CH}{}_2\mathrm{NH}{}_2$ : strong band near $1715\mathrm{c}{\mathrm{m}}^{-1}$ due to C=O
4. Dethanenitrile, $\mathrm{CH}{}_3\mathrm{CN}$ : band near $2250\mathrm{c}{\mathrm{m}}^{-1}$