What is the primary advantage of using an autoclave for sterilization?

The primary advantage of using an autoclave for sterilization lies in its high reliability in killing spores. Autoclaves utilize steam under pressure to achieve higher temperatures than boiling water alone, making them especially effective against resistant bacterial spores and other microorganisms. The combination of heat and moisture creates an environment that efficiently disrupts the cells, leading to their destruction. This characteristic is crucial in medical and laboratory settings, where safety and sterility are paramount.

While the other options present valuable points, they do not capture the central purpose of autoclaving as effectively as the ability to eliminate spores. For example, cost-effectiveness and speed can vary based on specific applications and configurations, and while autoclaves generally do not leave chemical residues, this is not their principal benefit compared to their spore-killing effectiveness. High reliability in destroying spores is the hallmark that distinguishes autoclaving from other sterilization methods, making it a preferred choice in many contexts.