Suppose that the treasurer of ABC Ltd decided not to pool cash to the central master account, instead each subsidiary manages their cash. If the bank lending rate is 6% and the borrowing rate is 4%, which of the following represents the aggregate interest earned/paid by the subsidiaries? 

a. R11 400 paid 

b. R42 000 paid. 

c. R53 400 paid. 

d. R60 000 paid.