See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Carbocation Stability Analysis **Identify the carbocation types:** - **(a)** Tertiary carbocation: $C^+$ bonded to 3 methyl groups - **(b)** Secondary carbocation: $C^+$ bonded to 2 methyl groups and 2 hydrogens - **(c)** Primary carbocation: $C^+$ bonded to 1 methyl group and 3 hydrogens - **(d)** Secondary carbocation: $C^+$ bonded to 1 methyl group and other alkyl substituents **Apply carbocation stability rules:** Carbocation stability follows: **Tertiary > Secondary > Primary** This is due to: - Hyperconjugation (orbital overlap with adjacent C-H bonds) - Inductive effects (alkyl groups donate electron density to the positive carbon) **Order by stability:** $$\text{(a)} > \text{(b)} = \text{(d)} > \text{(c)}$$ More precisely: $(a) > (b) > (d) > (c)$ or written as **$c < b > d > a$** This matches **(C) $c < b > d > a$** ✓ The answer is **(C)** because tertiary (a) is most stable, primary (c) is least stable, and the two secondary carbocations (b and d) fall in between with (b) being slightly more substituted than (d).