Aflea and dog are an example of , because the flea irritates the dog's skin and feeds on its blood. certain bacteria live in the digestive tract of humans, and their relationship is an example of because the bacteria humans to break down the food they eat. cattle egrets eat insects off the back of an elephant, which is an example of because the cattle egrets benefit without either harming or the elephants.

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.