The only negative ion found in KOH(aq) is

KOH(aq) dissociates in water to form K+(aq) and OH-(aq).

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

i think the answer is terrae but not 100 percent sure. ▓▬▬ §