The carbonyl group $\mathrm{C{=}O}$ is highly POLAR, with the oxygen bearing a partial negative charge and the carbon a partial positive charge. The principal consequence for the carbonyl group's reactivity is

1. Oxygen is much more electronegative than carbon, so it pulls electron density away from the C in the $\mathrm{C{=}O}$ bond. 2. Result: the carbon carries a partial POSITIVE charge ($\delta^+$) and the oxygen carries a partial NEGATIVE charge ($\delta^-$). 3. The electrophilic ($\delta^+$) carbon is then attacked by NUCLEOPHILES — species with lone pairs or available electron density (such as $\mathrm{CN^-}$, $\mathrm{H^-}$ from $\mathrm{LiAlH_4}$, primary/secondary amines, alcohols). 4. This NUCLEOPHILIC ADDITION is the dominant reaction class for carbonyl compounds — the foundation of aldol condensations, cyanohydrin formation, hemiacetal/acetal formation, etc. 5. Option B is the alkene-style reactivity (electrophilic addition), which carbonyls do NOT typically undergo. Option C contradicts well-known carbonyl chemistry. Option D ignores the strong polarity confirmed by dipole moment measurements ($\sim 2.5\,\text{D}$ for many ketones). _Source: NCERT Class 12 Chemistry Part 2, Ch 8, §8.1.2 + §8.4 (Carbonyl polarity, nucleophilic addition mechanism), p. 4 + p. 9._