The plant species are native to the region; they are _____ to the climate.

• A. Income
• B. Indigenous
• C. Indicate
• D. Incongruous

Answer: (B)

Indigenous is the right choice because it describes something that originates in and is naturally found in a particular place. Here, the plants being native to the region means they belong to that climate by nature, so saying they are indigenous to the climate communicates their natural presence and adaptation there. The other options don’t fit: income is money earned, indicate is a verb meaning to point out, and incongruous means not fitting or out of place, which would suggest a mismatch rather than a natural origin.