Identify which of these comma rules is used in each sentence

Mom flew to Chicago and landed at O'Hare International Airport, one of the busiest airports in the U. S.

The comma rule used in this sentence is to separate a nonessential clause or phrase.

Identify which of these comma rules is used in each sentence

Mom flew to Chicago and landed at O'Hare International Airport, one of the busiest airports in the U. S.
appositive
long introductory
compound sentence
item in series

The comma rule used in this sentence is to separate an appositive.

Identify which of these comma rules is used in each sentence

If I win tickets to the concert, I will go with my best friend.
long introductory
compound sentence
item in series

The comma rule used in this sentence is a long introductory comma.

Identify which of these comma rules is used in each sentence

Leo ran down the block, across the street, through the park, and into the library.
compound sentence
item in series

The comma rule used in this sentence is an item in a series comma.