Success story tells about how a business person or people were able to overcome difficulty and setbacks in the business and has recorded a successful business after all the difficulty they encountered. Some business people say it to encourage others who are still finding it difficult and to also motivate themselves.
The answer is 4, because if the ants smell the same dead smell on this particular ant in the colony, their initial reaction is to eliminate it. The chemical sprayed upon the ant acts as a stimulus for a particular behavior.