Note the relationship between the first two word and suggest the suitable word/words for the fourth place:
(a) Lub: atrioventricular valves:: Dup:
(b) Coronary artery: Heart:: Hepatic artery:
(a) Lub: Atrio-ventricular valve:: Dup: Semilunar valves
(b) Coronary artery: Heart::Hepatic artery: Liver