The correct option is D A 0.2% solution of phenol is an antiseptic while 1% solution acts as a disinfectant
Antiseptic and disinfectants both either kill or prevent the growth of microorganisms. The main point of difference between these two is that the former (antiseptic) are used for living beings whereas disinfectants are not safe for living tissues.
A substance like phenol in its lower concentration (0.2%) behaves as antiseptic whereas in higher concentration (1%) as a disinfectant.
Chlorine is a strong disinfectants whereas dilute solutions of boric acid and hydrogen peroxide are mild antiseptic.
Hence, option (a), (c) and (d) are true.