Agar medium is composed of:

A. Robert Koch: Koch established methods for isolating and identifying bacteria and formulated Koch’s postulates, which advanced bacterial microbiology.
B. Joseph Lister: Lister pioneered antiseptic surgical techniques using carbolic acid and promoted reduction of infection in surgery.
C. Louis Pasteur: Pasteur’s work on infectious agents, fermentation, and vaccines helped shape the idea of invisible infectious agents and paved the way for the later concept of viruses.
D. Robert Hook: Hooke made early microscopic observations (cells) in the 17th century and was not involved in introducing the concept of viruses.

A. Refers to the spontaneous generation of organism from nonliving matter: Abiogenesis historically denotes the idea that life can arise spontaneously from nonliving material.
B. Explain the development of life forms from preexisting life forms: This describes biogenesis -the concept that life arises from existing life.
C. Only takes place in the absence of aseptic technique: Abiogenesis is a hypothesis about origins of life, not a lab event that simply depends on aseptic technique.
D. Was supported by Pasteur's swan-necked flask experiments: Pasteur’s swan-neck flask experiments actually refuted the spontaneous-generation idea under the conditions tested, so they did not support abiogenesis.