What is the result of using mylist[-1]?

Using mylist[-1] in Python directly accesses the last element of the list. Python supports negative indexing, which allows you to retrieve elements from the end of the list without needing to know its length. When you use -1 as the index, it refers to the last item, -2 refers to the second to last item, and so forth. This feature is particularly useful when you want to get the last element without calculating the total length of the list.

This behavior stands in contrast to positive indexing, which starts from zero; thus, mylist[0] would access the first element. As a result, this distinction clarifies why the other choices do not correctly describe the outcome of the operation. Slicing the list involves using the colon (:) operator, and there's no error unless the list is empty or the index is out of bounds when using positive indices.