Concept:Blood travels from the heart to tissues through vessels that gradually become smaller.Explanation:Arteries carry blood away from the heart.They branch into smaller vessels called arterioles.Arterioles supply blood to the capillary networks in the tissues.Therefore, the correct route from the heart to the tissues is: heart → artery → arteriole → tissues.Veins and venules carry blood back to the heart, so they are not part of this outward pathway.Answer:B. heart-artery-arteriole-tissues