Final answer:
The correct verb phrase to complete the sentence is 'thrive'. Capybara colonies naturally prosper or grow well in a rainforest environment.
Step-by-step explanation:
The correct verb phrase to complete the sentence is thrive.
In the sentence, 'A capybara colony naturally thrives in a rainforest environment,' the verb 'thrives' is used to show that capybara colonies naturally prosper or grow well in a rainforest environment.
Therefore, option C, thrive, is the verb phrase that best completes the sentence.
Learn more about English