Similarly, after solid A is added to the right plate for full reaction, the mass of the substance in the beaker is m (hydrochloric acid) +m (solid A)-m (evolved gas).
Because the mass of hydrochloric acid initially added is equal to the mass of solid, if the balance pointer is biased to the left plate, that is, the mass of substances in the beaker of the left plate is large, then the mass of gas escaping from the right plate must be greater than that of H2 escaping from the left plate.
By analyzing the four options, it can be found that B with sodium hydroxide does not evolve gas, C with copper does not react, that is, D with iron oxide does not evolve gas, and only A has evolved gas, which is greater than the hydrogen mass released by zinc.
So choose one