Which of the following is considered a bactericide?

A bactericide is a substance that kills bacteria, and among the options provided, a disinfectant fits this description as it is specifically designed to eliminate bacteria and other microorganisms on surfaces. Disinfectants are often used in cleaning and sanitizing environments to ensure that harmful bacteria are killed, making them effective in controlling infections and ensuring hygiene.

While antiseptics are also effective in reducing or preventing bacterial growth on living tissues, they do not typically kill bacteria outright in the same way that disinfectants do on surfaces. Antibiotics are substances that kill or inhibit bacterial growth but are specifically used in a medical context to treat infections within the body rather than as cleaning agents. Preservatives are substances added to food to prevent spoilage caused by microbial growth but do not necessarily kill bacteria directly.

Thus, a disinfectant is primarily characterized by its ability to kill bacteria, which is why it is considered a bactericide.