Viable material of endangered species can be preserved by

The correct answer is A. Gene bank.

A gene bank is a facility that stores genetic material, such as seeds, tissue samples, and DNA, for the purpose of conservation and research. Gene banks play an important role in protecting endangered species by ensuring that their genetic material is available for future use.

A gene library is a collection of DNA sequences that have been cloned into a vector, such as a plasmid or a virus. Gene libraries are used to study the genomes of organisms and to identify genes that are responsible for specific traits.

A gene pool is the total genetic variation within a population of organisms. Gene pools are