In Browne's classification of placenta pre, the placenta covers the internal os when closed but not when fully dilated is:

Browne's classification for placenta pre: Type 1 lateral Placenta dipping into the lower segment but reached upto the os Type 2 marginal Placenta edge reached the internal os Type 3 The placenta covers the internal os when closed but not when fully dilated Type 4 The placenta covers the internal os even fully dilated