Use repeated subtraction to divide 86 divided by 9

-- Start with 86.

-- Subtract 9 the first time.        You have  77 left.

-- Subtract 9 the 2nd time.        You have  68 left.

-- Subtract 9 the 3rd time.        You have  59 left.

-- Subtract 9 the 4th time.        You have  50 left.

-- Subtract 9 the 5th time.        You have  41 left.

-- Subtract 9 the 6th time.        You have  32 left.

-- Subtract 9 the 7th time.        You have  23 left.

-- Subtract 9 the 8th time.        You have  14 left.

-- Subtract 9 the 9th time.        You only have 5 left, so you can't subtract 9 again.

                                                 You subtracted it 9 times, and you have 5 left.

                                                 So  86  divided by 9 is  (9 with remainder 5) .

So don't take my word i'm not exactly a mathematical person but i would assume a. because while selling the soap every month you increase in sells so you would by 11 percent. the you would get the factor 0.89 which if i had to guess would be the monthly profit over 11 probably wrong tho