Suppose That the Following Regression Equation Best Describes the Co-Movement $\frac { \sum _ { i = 1 } ^ { N } e _ { i } } { N }$

Suppose that the following regression equation best describes the co-movement between Sales, Price and Number of Competitors: Sales_i = B + M₁Price_i + M₂NumComp_i. What moment condition would not be used to yield a consistent estimate of B, M₁, M₂?

A) $\frac { \sum _ { i = 1 } ^ { N } e _ { i } } { N }$ = 0
B)

$\frac{\sum _ { i = 1 } ^ { N } \left( \text { Sales } _ { i } - b - m _ { 1 } \text { Price } _ { i } - m _ { 2 } \text { Num Comp } _ { i } \right) \text { Price } _ { i }}{N}$ = 0
C)


$\frac{\sum _ { i = 1 } ^ { N } \left( \text { Sales } _ { i } - b - m _ { 1 } \text { Price } _ { i } - m _ { 2 } \text { NumComp } _ { i } \right) }{N}$ = 0
D)

$\frac{\sum _ { i = 1 } ^ { N } \left( \text { Sales } _ { i } - b - m _ { 1 } \text { Price } _ { i } \right) \text { Price } _ { i }}{N}$ = 0