On January 1, 2016, Rainbow Corporation agreed to grant all its employees two weeks paid vacation each year, with the stipulation that vacations earned each year can be taken the following year. For the year ended December 31, 2016, Rainbow's employees each earned an average of $600 per week. A total of 8,000 vacation weeks earned in 2016 were taken during 2016 and a total of 12,000 vacation weeks earned in 2016 were not taken during 2016. Wage rates for employees rose by an average of 5 percent by the time vacations actually were taken in 2017. What is the amount of wages expense related to 2016 vacation time?

a. $4.8 million b. $7.2 million c. $9.6 million d. $12.0 million