KBC 2023| What is a herbicide used to kill? KBC 2023, Check the answer to the question- What is a herbicide used to kill? By Himani Budakoti - August 31, 2023 KBC 2023, Amitabh Bachchan. (Representative Image) KBC 2023, The options of the question – What is a herbicide used to kill? A. Earthworms B. Birds C. Weeds D. Fish The answer is C. Weeds.