To which subset of real numbers does the number one-fifth belong? A. irrational numbers
B. rational numbers
C. whole numbers, integers, rational numbers
D. whole numbers, natural numbers, integers

Is it A? Thanks!

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