Answer:
C. foreign
Step-by-step explanation:
An antonym can be defined as a word having the opposite meaning of another word.
For example, full is antonym of empty, tall is antonym for short, fat is to thin, happy is to sad, rich is to poor, light is to darkness, hot is cold, dry is to wet, etc.
Indigenous refers to a situation in which a person is born and a native of a particular town, village or state. Thus, he or she is engendered in that land or region and as such shall be referred to as an indigene.
Hence, the closest antonym for the word indigenous is foreign because if you're not a native of a particular region, you're referred to as a foreigner.