Which sub contains onion, lettuce, and sauce as ingredients?

The sub that contains onion, lettuce, and sauce as ingredients is the Italian Night Club. This sandwich is known for its combination of meats and fresh toppings, including onion, which adds a sharp flavor, along with crisp lettuce that provides texture and freshness. The sauce used in this sub enhances the overall flavor profile, making it a popular choice among customers.

In contrast, the other options either contain a different set of ingredients or do not include all three specified components. For example, some may have different types of vegetables or sauces that do not meet the criteria outlined in the question. The Italian Night Club specifically aligns with the ingredients mentioned, making it the correct choice.