An 8 year old patient with all primary molars still present exhibits a cusp-to-cusp relationship of permanent maxillary and mandibular first molars. The management of this patient should be to

observe.

disk the distal surfaces of primary mandibular second molars to allow normal adjustment of permanent molars.

place a cervical headgear to reposition maxillary molars.

refer the patient to an orthodontist for consultation.

plan serial extractions for more normal adjustment of the occlusion.