A trader sells soaps in economy packs of four soaps per pack, each pack being charged at the listed price of three soaps. For every set of five such packs bought by a customer, the trader gives him one extra soap as a free gift. If a customer buys 12 economy packs, what is the effective percentage of discount that he gets?

Options

A. `28%`
B. `28 4/7%`
C. `4%`
D. `35 5/7%`

Answer

A