Final answer:
The Criminal Code of Canada provides the authority for a security guard to make an arrest for theft.
Step-by-step explanation:
The federal law that gives a security guard the authority to make an arrest of a person who committed a theft is C. The Criminal Code of Canada. Security guards are typically granted certain powers under provincial legislation and the Criminal Code, which enables them to perform citizen's arrests in certain circumstances, such as when they catch an individual in the act of committing a criminal offense on or in relation to the property they are protecting. The other options listed do not pertain to the authority for making arrests for theft offenses.