Final answer:
Disinfection is not effective against bacterial spores (option A). Bacterial spores can resist the disinfecting properties of low and intermediate-level germicides, which can otherwise kill vegetative cells, some viruses, and fungi.
Step-by-step explanation:
Disinfection is not effective against bacterial spores. Disinfectants are chemical agents used to reduce the number of pathogens on surfaces to a safe level. However, not all disinfectants are created equal in their ability to kill different types of microbes. High-level germicides can lead to sterilization by killing vegetative cells, fungi, viruses, and endospores.
Intermediate-level germicides have limited effectiveness against endospores and certain viruses, while low-level germicides can kill vegetative cells and some enveloped viruses but are ineffective against endospores. Since bacterial spores are resistant forms of bacteria that can survive harsh conditions, including many disinfection processes, they are not killed by low and intermediate-level disinfectants.