Identify product [A], [B] and [C] in the following reaction sequence:

Step 1: Pd/C + H$_2$ (Lindlar-type) -- partial hydrogenation

Propyne $\ce{CH3-C≡CH}$ + 1 mol $\ce{H2}$ with $\ce{Pd/C}$ $\rightarrow$ propene $\ce{CH3-CH=CH2}$ (syn addition, cis alkene from internal alkynes; terminal gives propene directly).

$[A] = \ce{CH3-CH=CH2}$

Step 2: Ozonolysis with reductive workup (Zn/H$_2$O) Key Points:

• $\ce{Pd/C}$ + $\ce{H2}$: reduces alkyne $\rightarrow$ alkene (1 mol $\ce{H2}$)
• Reductive ozonolysis: $\ce{RCH=}$ $\rightarrow$ $\ce{RCHO}$; $\ce{=CH2}$ $\rightarrow$ $\ce{HCHO}$
• Oxidative workup ($\ce{H2O2}$) would give $\ce{RCOOH}$ instead