Answer:
The answer to your question is: letter A
Step-by-step explanation:
A combination reaction is when there are two reactants that gives only one product.
a. 2SO2 + O2—> 2SO3 This is a combination reaction,
2 reactants gives one product.
b. Zn + Cu(NO3)2–>Zn(NO3)2 + Cu This is not a combination reaction,
it's a single replacement reaction.
c. 2H2O2–> 2H2O+O2 This is a decomposition reaction
d. AgNO3 + NaCl → AgCl+NaNO3 THis is a double replacement reaction.