Given the model y = XB+u where the error w is white noise, consider a generic linear estimator B = [(X'x)-x'+ Cly (a) Obtain the condition on C for...

I'm looking for a solution for this exercise. An explanation would be great

Thanks in advance

7. Given the modely = XB+uwhere the error w is white noise, consider a generic linear estimatorB = [(X'x)-x'+ Cly(a) Obtain the condition on C for which E(B) = 6(b) Assuming that condition derived in (a) is satisfied, obtain the con-dition on C such that B'X'e = 0, where e is the vector of residuals.