Which of the Following Is the Best Example of a Marginal

Which of the following is the best example of a marginal change?

A) After graduating from university, Audrey's income increases from $500 per month to $3000 per month.
B) Morgan gets a raise at her part-time job and is now paid $10.25 per hour instead of $10.00.
C) Housing prices in an area increase by 40% when a new highway is built in a small town.
D) A hard freeze wipes out half of the tobacco crop in Ontario and the price of cigarettes doubles.