Given the answer options, I agree that the sp_foreachtable option was the only correct one.

But that does not make this the recommended method to disable all triggers in a database. As can be read in the documentation that is referenced in the explanation, a better way would be

DISABLE TRIGGER ALL ON DATABASE;

EDIT: The above is NOT TRUE!!! Hrovje alerted me to this mistake. This will not disable table- and view-scoped triggers, but only database-scoped DDL triggers. My apologies for the confusion.