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