Two numbers are respectively 71% and 80% more than a third number. The percentage that is first of the second is? Choose the correct choice from the following options:
A) 4 %  B) 5 %  C) 6 %  D) 7 %  E) 8 %

Rationale: "i ii iii 171 180 100 180 - - - - - - - - - - 171 100 - - - - - - - - - - - ? = > 5 % answer : b"
Answer: B