Race is to biology as ethnicity is to

Biology refers to the scientific study of life and living organisms, which does not encapsulate the broader social and cultural implications that ethnicity entails. While race has biological connotations, ethnicity is not merely a biological concept; it significantly involves cultural identity, making this option incorrect.

Language is an important aspect of culture and can vary within ethnic groups. However, ethnicity is a more encompassing term that includes language as one of its many components, such as traditions, customs, and shared history. Therefore, while related, language does not fully capture the essence of ethnicity.

Region refers to a geographical area, which may influence cultural practices but does not define ethnicity on its own. Ethnicity transcends geographical boundaries and is more centered on the shared cultural traits of a group, making this choice insufficient in accurately representing the relationship.