You are presented with the quiz "Which is an invertebrate mollusk?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "mollusks are invertebrates such as the common snail" and "abalone are marine snails". So, what's the best answer to the question?
Select from: 1). ferns 2). Newton 3). a fish 4). Ant 5). tortoises 6). Swordfish 7). Abalone 8). Crab
Answer:
7).