Identify the substituents in each of the following compounds as inductively electron-withdrawing, electron-donating by hyperconjugation, electron-withdrawing by resonance, or electron-donating by resonance.
a. —Clb. —CH₃
c. —CHO

• A. (a). electron-withdrawing inductively and electron-donating by resonance
  (b). electron-donating by hyperconjugation
  (c). electron-withdrawing both by resonance and inductive effect.
• B. (a). electron-donating inductively and electron-withdrawing by resonance
  (b). electron-donating by hyperconjugation
  (c). electron-withdrawing both by resonance and inductive effect.
• C. (a). electron-withdrawing inductively and electron-donating by resonance
  (b). electron-donating by hyperconjugation
  (c). electron-donating both by resonance and hyperconjugation.
• D. (a). electron-donating inductively and by resonance
  (b). electron-donating by hyperconjugation
  (c). electron-withdrawing both by hyperconjugation and inductive effect.

Answer: (A)