Environments are covered with manmade structures like roads, buildings, and sewers. Green spaces such as parks, backyards, and undeveloped lots are scattered in among the developed areas instead of all connected together. Plants and animals have to deal with exposure to toxins from vehicles and loss of habitat and food sources. These are all ways that _______.
a. humans have intervened to both manage and manipulate the environment to ensure species survival
b. nonhuman life in an urban ecosystem differs from that in an undeveloped forest ecosystem
c. cities have been developed to keep wildlife out of public areas
d. humans have impacted the environment and caused wildlife species to become domesticated