Given the quadratic equation below, determine which it could represent.
x^2-4x=60

a: a wall in liza's bedroom has an area of 60 square feet. she covers 4 square feet of the wall with a poster.
b: on tuesday, a packaging company packed 4 fewer boxes of cashews than they did on monday. they packed a total of 60 boxes.
c: in a meeting room for a business event, there are 4 fewer chairs laid out in each row than the number of rows. the total number of chairs in the room is 60.
d: mr. bass is 4 years older than his sister. the total of their ages is 60 years.