Final answer:
The formula for carbon tetraiodide is CI4, as 'tetra-' indicates the presence of four iodine atoms.
Step-by-step explanation:
The formula for carbon tetraiodide is represented by the prefix 'tetra-' indicating four iodine atoms bonded to a single carbon atom. Hence, the correct formula is CI4. This chemical naming is in line with other compounds where the prefix indicates the number of each type of atom, such as carbon tetrachloride (CCl4), silicon dioxide (SiO2), and trisilicon tetranitride (Si3N4).