What is the average weighted price change illustrated by the table below?

Product Percentage if income spent on the product $(\%)$ Price change $(\%)$

P $10+8$

Q $15+6$

R $25+4$

S $50-9$

A$)4\mathrm{.}5\%$

B$)7\mathrm{.}2\%$

C$)9\mathrm{.}0\%$

D$)-1\mathrm{.}8\%$