Which statement is modeled by the expression? 150/k

a. A librarian had 150 books to be placed on shelves with an equal number of books on each shelf. If k is the number of shelves to be used, then 150k is the number of books on each shelf.

b. The Henderson family drove 150 miles each day of their vacation. If their vacation lasted for k days, then 150/k is the total number of miles they traveled on their vacation.

c. Cory had 150 dollars in his savings account. He withdrew k dollars to buy a catcher's mitt. He then had 150/k dollars left in his savings account.

d. The cafeteria has a capacity of 150 seats. If k is the number of people in the cafeteria at lunch time, then 150/k is number of seats that were not used at lunch time.