Which group is the highest on the social scale? A. Craftspeople
B. Merchants
C. Scribes
D. Slaves

the technology changed agriculture in an impacting manner since many people left the field work by a cellular or other technological appliances

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."