13. When you have three or more items in a series, the final comma before the conjunction (and, or, nor) is
A. confusing
B. a comma splice
O C. optional.
D. necessary.

Answer :

The question concerns the use of the comma in a list of three or more items, specifically the final comma used before the conjunction (such as "and", "or", "nor"). This final comma is known as the Oxford comma or serial comma.

To explain in detail:
- The Oxford comma is placed immediately before the coordinating conjunction in a list of three or more items. For example: "I bought apples, oranges, and bananas."
- Without the Oxford comma, the sentence would be: "I bought apples, oranges and bananas."

Consider the following sentence:
- "I bought apples, oranges, and bananas."
Here, using the Oxford comma provides a clear separation of each item in the list.

Conversely:
- "I bought apples, oranges and bananas."
Without the Oxford comma, this can sometimes lead to ambiguity or misinterpretation, as it might imply a grouping between "oranges and bananas."

The use of the Oxford comma is a style choice. While some style guides consider it optional, others, such as the Chicago Manual of Style and the MLA (Modern Language Association) recommend using it to avoid confusion.

Given the options:
A. Confusing – This is not accurate, as the Oxford comma actually helps in reducing confusion.
B. A comma splice – This is incorrect terminology for the context. A comma splice occurs when two independent clauses are joined with just a comma.
C. Optional – While the Oxford comma can be optional depending on the style guide, it is generally seen as beneficial and thus not the best answer here.
D. Necessary – This is the most accurate answer in the context of ensuring clarity and preventing potential ambiguity in a series.

Therefore, the correct answer is:
D. necessary.