What is the name of a classic sauce from which other sauces can be derived?

The correct answer is the term "Mother Sauce," which refers to a fundamental sauce in the culinary world that serves as the base for a variety of derivative sauces. Classic mother sauces include béchamel, velouté, brown sauce (espagnole), tomato sauce, and hollandaise. Each of these can be further modified or combined with other ingredients to create secondary sauces, also known as "daughter sauces." This system of categorizing sauces not only helps cooks understand the relationships between different sauces but also encourages creativity in sauce-making.

While the term "Base Sauce" might suggest a foundational element, it lacks the established culinary recognition that mother sauces have. "Stock Sauce" is not a standard culinary term. Additionally, "Finishing Sauce" refers more to sauces used to enhance the flavor of a dish just before serving, rather than being a foundational sauce from which others are derived. Hence, the mother sauce distinction is essential for understanding classical French cooking and many modern culinary practices.