Final answer:
The correct change to improve the sentence is to a. remove the comma after 14.
Step-by-step explanation:
The correct change that should be made to the sentence is to remove the comma after 14. In this sentence, the comma is unnecessary and creates a grammatical error. Therefore, option a. Remove the comma after 14 is the correct answer.
Commas are often used to separate clauses in a sentence. For example, 'I finally found my keys, and I got to work just in time.' In this sentence, the comma is placed before the coordinating conjunction 'and' that separates two independent clauses.