Which of the following is not a standard ingredient in a Classic Eggs Benedict?

In a Classic Eggs Benedict, the traditional components include poached eggs, Canadian bacon (or sometimes ham), and Hollandaise sauce served on an English muffin. Spinach is not part of this classic recipe, making it the correct choice for what is not a standard ingredient.

The dish is known for its rich flavors and textures, where the poached eggs provide a runny yolk, the Canadian bacon adds a savory element, and the Hollandaise sauce offers a creamy, buttery quality. Although variations of Eggs Benedict exist, such as Florentine Benedict which includes spinach, the classic version does not incorporate spinach. Therefore, identifying spinach as not being part of the classic dish highlights the specific composition that defines Classic Eggs Benedict.