问题如下：
Which of Vasileva’s assumptions regarding regression analysis is incorrect?
选项：
A.Assumption 1
Assumption 2
Assumption 3
解释：
C is correct. The assumptions of the linear regression model are that the 1) the relationship between the dependent variable and the independent variable is linear in the parameters b0 and b1; 2) the independent variable is not random; 3) the expected value of the error term is 0; 4) the variance of the error term is the same for all observations; 5) the error term is uncorrelated across observations; and 6) the error term is normally distributed. Assumption 3 is incorrect because the expected value of the error term is assumed to be zero, not equal to the mean of the dependent variable.
assumption 2为什么正确，应该表述为constant and stable而不是same吧？谢谢
