<prompt> The after coming head of the baby in a breech delivery can be arrested by all of the following except:Extended headHydrocephalusPlacenta preIncomplete dilatation of the cervix  <response>: If a whole baby can make its way from breech onwards till the head, then even if there is a placenta pre, it will not obstruct the fetal head to come though since there was no obstruction to the whole fetus. 