MA1 – Labour and Remuneration Costs (Multiple Choice Question)

I recently did a Multiple Choice Question Test and I tried to work out this question but to no avail. Any answers given will be greatly appreciated. Thank you.

Management are thinking of changing the remuneration method to a piecework system where
employees are paid $4.10 per unit for each unit they produce for the first 40 units and $4.70 per unit for any units produced over and above 40. Employees are expected to produce 45 units per week under this system.

What is the change in unit labour cost from the current system to the proposed piecework
system?

a) $4.17 increase
b) $0.93 decrease
c) $4.17 decrease
d) $492 decrease