A manufacturer sells goods at $4 per unit to stockists after a 10% profit. The stockists then sell the goods to distributors at 25% profit. The distributor adds a 20% profit on it and sells it to a retailer.
If the retailer sells the goods to the end customer at 10% profit, then what does each unit of the goods cost to a customer?
(A) 4
(B) 5
(C) 6
(D) 6.6
(E) 7