Which was not a problem faced by farmers in the late 19th century?
a. overproduction on the great plains led to a drop in crop prices.
b. rising city populations were willing to pay higher prices for food.
c. railroads and grain elevator owners were making huge profits on farmers.
d. famers owed money on loans for farm machinery, improvements and bad times.

answer; self_ disclosure;

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."