Final answer:
Most written recipes calling for fresh shell eggs are based on the use of option b. large eggs. This standard helps maintain ingredient consistency and ensures that the recipe turns out as intended.
Step-by-step explanation:
The size of egg that most written recipes assume when they call for fresh shell eggs is large. This is a standard convention used across many recipes, as it provides a consistent quantity for ingredients lists and ensures that the dish turns out as intended. When a recipe specifies 'one egg' without indicating a size, it is typically a large egg that is meant. If a different size is used, such as a medium, extra large, or jumbo egg, the proportions in the recipe may need to be adjusted accordingly.