Why is the preservation of ancestor species, such as Mexican teosinte (Zea diploperennis), important in the context of human welfare?

A) Edible species, such as Z. diploperennis, can be used for food if all our food crops become extinct.
B) Species such as Z. diploperennis can be used to manufacture anticancer drugs.
C) Genes for pest resistance from species such as Z. diploperennis can be transferred to food crops.
D) Genes from species such as Z. diploperennis can be inserted into imperiled livestock varieties to help prevent them from becoming extinct.