Explain how two caracters depend on each other

Plants and animals depend on each other for several reasons, including production of food, eradication of harmful pests and even propagation. Some interactions between plants and animals are detrimental, such as the serious injury or harm that occurs when animals eat toxic plants. Other relationships, however, like pollination, benefit both species.

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."

propioception;