$\text {where \(Q\) is the quantity demanded of good \(A ; P A = \$ 10\), price of good \(A ; P _ { B } = \$ 8\), price of good }$

$$\mathrm { Q } = - 6,500 - 100 \mathrm { P } _ { \mathrm { A } } + 50 \mathrm {~PB} + .3 \mathrm { I } + .2 \mathrm {~A} ; \mathrm { R } ^ { 2 } = .12 , ( 2,500 ) ( 50 ) ( 30 ) ( .1 ) ( .08 )$$
$\text {where \(Q\) is the quantity demanded of good \(A ; P A = \$ 10\) , price of good \(A ; P _ { B } = \$ 8\) , price of good }$
$\text {\(B ; I = \$ 12,000\) , per capita income; and \(A = \$ 20,000\) , monthly advertising expenditures.}$
-As a researcher,which aspect of the results would be of greatest concern?

A) the negative value of the constant
B) the relatively low impact of the competitor's price
C) the fact that not all of the variables are statistically significant
D) the poor fit of the regression line