Im not 100% sure, but I think the answer is C. If not, Im sorry for bothering you.
Answer:D - adding a catalyst
Explanation:
Reactivity of Group 1 and 2 elements increases as you go down the periodic table. So sodium is more reactive than lithium. Sodium will react with oxygen forming Na2O (sodium oxide). Lithium forms lithium oxide (Li2O).
I dont know the answer sorry follow me for a follow back