Explanation

Plant sterols such as stigmasterol, ergosterol and sitosterol, which structurally resemble animal cholesterol, are collectively termed phytosterols ('phyto' = plant). Calciferols are the vitamin D group, ergocalciferol is specifically vitamin D2, and lumisterol is a photochemical precursor in vitamin D synthesis, none of which is the general term for plant sterols. The correct generic name is therefore phytosterols, option (A).