Final answer:
Disinfectants are not pesticides.
Step-by-step explanation:
Disinfectants are not pesticides, so (a) is not true. Disinfectants are antimicrobial chemicals that are used to kill or inactivate microorganisms on nonliving surfaces. They are different from pesticides, which are used to kill pests such as insects, rodents, or weeds. Therefore, the correct answer is (a) They are pesticides.