A 45 year old patient has 32 unrestored teeth. The only defects are deeply stained grooves in the posterior teeth. Clinical examination reveals no evidence of caries in the grooves. The treatment of choice is

no treatment.

application of cyanoacrylate pit and fissure sealants.

application of BIS-GMA pit and fissure sealants.

conservative Class I amalgams.

prophylactic odontotomy