X Co's employees carry out work to the value of $7500. They are paid $4500 immediately with the balance to be settled in the next accounting period. Under the accrual approach to profit measurement, the amount of wages expense that will be recorded in the current period is:

a) Nil

b) $4500

c) $3000

d) $7500

I'm not sure what the answer is and I don't know how to work it out.