Your answer would be a change in odor! Hope this helps! ;D
I would say the answer is A.
Answer:
See below
Explanation:
Each metal oxide reacts with HCl to form water and the metal chloride

Answer:
2As2S3 + 9O2 = 2As2O3 + 6SO2
Explanation:
I don’t understand. Is there a picture? Where are the options?