Reactivity towards nucleophilic addition is governed by steric hindrance and $+I$ electron donation:

• Ketones are less reactive than aldehydes because two alkyl groups hinder attack and reduce partial positive charge on carbonyl carbon.
• Between the two ketones, butanone ($\text{CH}_3\text{COCH}_2\text{CH}_3$) has greater steric hindrance than propanone ($\text{CH}_3\text{COCH}_3$). Thus: Butanone (D) < Propanone (B).
• Between the two aldehydes, propanal ($\text{CH}_3\text{CH}_2\text{CHO}$) has larger steric hindrance than ethanal ($\text{CH}_3\text{CHO}$). Thus: Propanal (C) < Ethanal (A).
  Increasing order: Butanone (D) < Propanone (B) < Propanal (C) < Ethanal (A).

Reactivity towards nucleophilic attack on carbonyl carbon depends on steric and electronic factors:

• Ketones are less reactive than aldehydes due to greater steric hindrance and electron donation from the methyl group. Hence, Acetophenone is the least reactive.
• Among aromatic aldehydes, electron-donating groups ($-\text{CH}_3$) reduce electrophilicity: p-Tolualdehyde < Benzaldehyde.
• Strong electron-withdrawing groups ($-M/-I$ of $-\text{NO}_2$) strongly increase the positive charge on carbonyl carbon, making p-Nitrobenzaldehyde the most reactive.
  
  Increasing order: Acetophenone < p-Tolualdehyde < Benzaldehyde < p-Nitrobenzaldehyde.