What Are the Implications for 2SLS Estimators If Reduced Form

Multiple Choice

What are the implications for 2SLS estimators if reduced form parameter estimates are statistically insignificant?

A) still consistent in large samples,but no longer BLUE
B) there will be correlation in the structural equations,causing estimators to be inconsistent
C) there are no consequences,only structural parameters matter
D) small sample properties no longer hold,but asymptotic properties still apply