Final answer:
The formula XeO3 indicates that there are three oxygen atoms bonded to one xenon atom, so the answer is Option 3: 3 oxygen atoms.
Step-by-step explanation:
The chemical formula for xenon trioxide is XeO3. This indicates that there is one xenon atom (Xe) bonded to three oxygen atoms (O). Hence, the number of oxygen atoms in the formula for xenon trioxide is three. Therefore, the correct answer to the question is Option 3: 3 oxygen atoms.