Refer to the Following:
the Following Linear Demand Specification Is $Q = a + b P + c M + d P _ { R }$

Refer to the following:
The following linear demand specification is estimated for Conlan Enterprises, a price-setting firm:
$Q = a + b P + c M + d P _ { R }$
where Q is the quantity demanded of the product Conlan Enterprises sells, P is the price of that product, M is income, and
$P _ { R }$ is the price of a related product. The results of the estimation are presented below:
$\begin{array}{rllll}\text { DEPENDENT VARIABLE: } & Q & \text { R-SQUARE } & \text { F-RATIO } & \text { P-VALUEONF } \\\text { OBSERVATIONS: } 32 & 0.7984 & 36.14 & 0.0001\\\\\text { VARIABLE } & \text { PARAMETER } & \text { STANDARD } & & \\& \text { ESTIMATE } & \text { ERROR } & \text { T-RATIO } & \text { P-VALUE } \\\text { INTERCEPT } & 846.30 & 76.70 & 11.03 & 0.0001 \\\text { P } & -8.60 & 2.60 & -3.31 & 0.0026 \\\text { M } & 0.0184 & 0.0048 & 3.83 & 0.0007 \\\text { PR }& -4.3075 & 1.230 & -3.50 & 0.0016\end{array}$
-At the 1% level of significance, which estimates are statistically significant?

A) All are statistically significant
B) All but $\hat { a }$ are statistically significant
C) Only $\hat { a } , \hat { b } \text {, and } \hat { c }$ are statistically significant
D) Only $\hat { a }$ is statistically significant
E) All but $\hat { b } \text { and } \hat { d }$ are statistically significant