Which of the following poses the greatest risk for species extinction? a.) expansion of human cities b.) increased levels of pollution c.) inset seems hurricane activity d.) uv radiation and the hole in the ozone layer

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism