Final answer:
High temperature does not reduce the efficacy of a disinfectant but enhances it, unlike the presence of organic matter, pH extremes, or insufficient contact time, which can all compromise effectiveness.
Step-by-step explanation:
The question asks which factor does NOT reduce the efficacy of a disinfectant. The options are A) Presence of organic matter, B) High temperature, C) Prolonged contact time, and D) pH extremes. The correct answer is B) High temperature.
Higher temperatures typically increase the activity of disinfectants, thereby making them more effective at killing microbes. Conversely, the presence of organic matter (A) can indeed inhibit the effectiveness of a disinfectant, as can pH extremes (D). Prolonged contact time (C) usually enhances the efficacy of a disinfectant, as longer exposure times allow the chemical agent to work thoroughly. Hence, high temperature does not reduce the efficacy but rather enhances it.