What is the vertex of the graph of y = −1(x − 2)2 + 3?
(3,-2)
(-2,3)
(3,2)
(2,3)

The vertex form is y=a(x-h)²+k
the vertex is (h,k)
so

y=-1(x-2)²+3
compare to
y=a(x-h)²+k
2=h and 3=k
the vertex is  (2,3)
4th option

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