What are the advantages of Terai region in Nepal? Explain.

terai region is the main region for agriculture

agriculture production are supplied to all over country from this region

hope this will help you

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."