Answer:
double replacement
Explanation:
Double replacement reactions are where both cations and anions of reactants switch.
For eg: AB + CD -----> AD + BC (Here we see both things are replaced)
Synthesis reactions is where two simple things make one complex thing.
So A + B --- > AB
Combustion is usually reaction where Oxygen is reactant but here we don't have that.
Single replacement only replaces either cation or anion.
So AB + C .------> AC + B
