The presence of chemical fertilizer is loss of water causes the death of Aquatic life give reason

The answer for #3 is c but i don't know why

What effect might melting sea ice have for people who live in coastal areas?

Ants live on acacia trees in south america. the ants feed on sugars secreted by the trees. the trees provide room for the ants to live. the ants sting any other insect or animal that comes to eat the trees. what type of relationship is this?