To determine which reaction is a metal displacement reaction, we need to understand the nature of each reaction.$\\$A metal displacement reaction involves one metal displacing another metal from a compound.$\\$Let's analyze each option:$\\$Option 1: $2KClO_3 \rightarrow 2KCl + 3O_2 \\$• This is a decomposition reaction where potassium chlorate decomposes into potassium chloride and oxygen.$\\$Option 2: $Cr_2O_3 + 2Al \rightarrow Al_2O_3 + 2Cr \\$• In this reaction, aluminum displaces chromium from chromium(III) oxide to form aluminum oxide and chromium metal.$\\$• This is a metal displacement reaction.$\\$Option 3: $Fe + 2HCl \rightarrow FeCl_2 + H_2 \uparrow \\$• This is a single displacement reaction where iron displaces hydrogen from hydrochloric acid, forming iron(II) chloride and hydrogen gas.$\\$• This is not a metal displacement reaction as it involves a non-metal (hydrogen).$\\$Option 4: $2Pb(NO_3)_2 \rightarrow 2PbO + 4NO_2 + O_2 \uparrow \\$• This is a decomposition reaction where lead(II) nitrate decomposes into lead(II) oxide, nitrogen dioxide, and oxygen.$\\$Based on the analysis, the correct option is Option 2, where aluminum displaces chromium from chromium(III) oxide.$\\$Therefore, the correct answer is Option 2.