Chlorophenols impart unpleasant taste and odor to drinking water at con-centrations as low as 5 mg/m3. They are formed when the chlorine disin-fection process is applied to phenol-containing waters. What is the unpleasant taste and odor threshold in units of
(a) mg/L,
(b) tg/L,
(c) ppm,
(d) ppb?