Here is a pattern of dots.
How many dots will there be in Step 4

For me i think it'll land on blue

The answer would be a

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