Answer:
The correct answer is letter "A": Coworker's paycheck.
Explanation:
One of the uses of apostrophes (') in grammar is to show possession. In such a case, the apostrophe and an "s" are added to nouns at their end ('s). If the noun is plural ending with an "s" only the apostrophe (') is added. The other use of apostrophes is to show that words have been contracted (e.g. I am = I'm).
Thus, the noun "coworker" in its singular form shows possession in the phrase:
Coworker's paycheck.