Q: In this task, you are given a text which is the body of a document. You are given a question and options. Pick the correct number. Don't generate anything else apart from the numbers provided in options.
Context: The emperor shrimp (Periclimenes imperator) is a species of shrimp with a wide distribution across the Indo-Pacific. It lives commensally on a number of hosts including the sea slug Hexabranchus. A. J. Bruce first described it in 1967 based on eight specimens ranging from 4 millimetres (0.16 in) to 7.6 millimetres (0.30 in) and found Periclimenes rex to be its best resemblance.
Question: The document can be classified to which topic?
Options: 1)Building, 2)WrittenWork, 3)Artist, 4)Animal, 5)Athlete
A:
4