How is compound interest different than exponential growth?

Does the problem say y=x+4?

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

Hmm confusing don't understand