Which of the following is a DECOMPOSITION redox reaction?

1. A DECOMPOSITION redox has the form $C \rightarrow A + B$ with electron transfer. 2. Option A: $2\mathrm{KClO}_3 \rightarrow 2\mathrm{KCl} + 3\mathrm{O}_2$. One reactant, two products. Cl goes $+5 \rightarrow -1$ (reduction); O goes $-2 \rightarrow 0$ (oxidation). ✓ Decomposition redox. 3. Option B is a neutralisation (acid + base $\rightarrow$ salt + water). Acid–base, NOT redox — H stays $+1$, Cl stays $-1$, Na stays $+1$, O stays $-2$. 4. Option C is a COMBINATION redox (synthesis of ammonia), not decomposition. 5. Option D is a double-displacement / precipitation reaction with NO electron transfer. _Source: NCERT Class 11 Chemistry Part 2, Ch 7, §7.3.1 "Decomposition Reactions", p. 7-8._