Question

select the sentence that uses a serial comma correctly.
im great, at softball, tennis and track.
im great at softball tennis and track.
im great at softball, tennis, and track.
im great at, softball, tennis, and track.

Explanation:

A serial comma (Oxford comma) is placed before the coordinating conjunction (here "and") in a list of three or more items. The correct sentence must properly separate each item in the list with commas, including the final one before "and", without incorrect commas elsewhere.

1. The first option has an incorrect comma after "great".
2. The second option lacks commas to separate the list items.
3. The fourth option has an incorrect comma after "at".
4. The third option correctly uses commas to separate each list item, including the serial comma before "and".

Answer:

I'm great at softball, tennis, and track.