If we have omitted an important variable from our model, which of the following multiple linear regression (MLR) assumptions are violated?

If we have omitted an important variable from our model, which of the following multiple linear regression (MLR) assumptions are violated?

A. The errors for different observations are unrelated

B. The errors for different observations have the same variance

C. The error term is unrelated with the regressor

D. None of the stated options