Final answer:
Chlorhexidine gluconate is the topical antimicrobial agent known to be ototoxic. Antiseptics are used on living tissues for microbial control to prevent infection.
Step-by-step explanation:
The topical antimicrobial agent among the choices given that is considered ototoxic is chlorhexidine gluconate. Ototoxicity refers to the potential of certain substances to cause damage to the ear, particularly the cochlea or auditory nerve and sometimes the vestibular system, leading to hearing loss or imbalance. Antimicrobial agents like chlorhexidine gluconate can be ototoxic when they enter the middle or inner ear, thus it should be used cautiously to avoid ear exposure.
Regarding the second question, the agent suitable for use on tissues for microbial control to prevent infection is B. antiseptic. Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction. Examples include iodine, chlorhexidine, and alcohol. Disinfectants are similar to antiseptics but are generally used on surfaces or inanimate objects. Sterilants are agents that kill all forms of microbial life, and water, while essential for cleaning, is not an antimicrobial agent.