Final Answer:
To refer to 'green', you'd use the notation `e[2][2]`. This accesses the third list in the list `e` (index 2) and then retrieves the item at index 2 within that list.
Step-by-step explanation:
In the given code snippet, the variable `e` is a list containing three lists: A, B, and C. Each inner list holds three elements. To access 'green', which is in the third position of the third inner list, you use `e[2][2]`.
Breaking this down, `e[2]` refers to the third inner list in `e`. This gives us `[12, 'fish', 'green']`. Then, to extract 'green', you use `[2]` on this inner list, which retrieves the element at index 2 within that list, resulting in 'green'.
Notation like `e(2, 2)` or `e(2)(2)` is incorrect for accessing elements in a nested list in Python. Square brackets (`[]`) are used to access elements in a list by index. So, the correct way to access 'green' within the nested lists of `e` is to use the square bracket notation: `e[2][2]`. Other variations like `e(2, 2)` or `e(2)(2)` would not work in Python syntax for accessing elements within nested lists.