You Buy Some Furniture for $800 and Pay "No Interest

Multiple Choice

You buy some furniture for $800 and pay "no interest" for n-days.This means that after n-days,you owe the furniture company $800.However,there is an administration fee of $50 that you must pay today (when you buy the furniture) .If the rate of simple interest that you are being charged is 12.4%,what is n (Answer to nearest day) ?

A) 99 days
B) 184 days
C) 173 days
D) 196 days