Answer:
Definition 4
Step-by-step explanation:
In the sentence, "The marine biologist dumped a bucket of fish entrails into the water to attract sharks," the word "entrails" is used to refer to the innards or internal organs of the fish. This corresponds to Definition 4.
By dumping the fish entrails into the water, the biologist is using the inner workings or deep parts of the fish to attract sharks, as sharks are attracted to the scent and presence of prey. In this context, "entrails" specifically refers to the internal organs or innards of the fish, which are considered the remote or deep parts of the fish's body.