In a prostodontic clinic a partial laminar denture for the upper jaw is being made for a 53-year-old patient. Objectively: dental formula is 14, 13, 12, 11, 21, 22, 23, 24, 27. The teeth are firm, clinical crowns are tall with pronounced equator. X-ray shows no periapical changes in the periodontium of the abutment teeth. What clasp fixation is optimal for this patient?