A dishonest dealer professes to sell goods at the cost price but uses a weight of 850 grams per kg, what is his percent? Choose the correct choice from the following:
A) 25 %
B) 17 %
C) 29 %
D) 55 %
E) 45 %

Rationale: "850 - - - 150 100 - - - ? = > 17.64 % answer : b"
Answer: B