The "scar" in the Lord of the Flies refers to..

A rip in the forest caused by the crash landing of the boys' plane on the island. The scar symbolizes that man, and his savage nature, destroys paradise merely by entering it.

Explanation:

halibut, flounder, tuna, and trout are all fish. so your first answer is 1.) fish. and since fish is edible, your next answer would be 3). edible

to describe those fishes more thoroughly, some of those fishes live in fresh water, and some of the fishes live in salt water, and that is not a thing that they all have in common. the question is asking what is common with all of the fish, so answer choices 2). fresh water and 4). salt water are not right.