Which punctuation change will correct this sentence Todays test cover the following marks comma semicolon and colon?

The correct punctuation change is to replace the comma after "marks" with a colon.

Here's the corrected sentence:

Today's test covers the following marks: comma, semicolon, and colon.

Here's why:

* Colons introduce lists. The colon after "marks" signals that a list of marks will follow.

* Commas separate items in a list. The commas between "comma," "semicolon," and "colon" are correct.