3. Part of Hinduism was a rigid social structure based on birth that existed until 1950 called this... (5 Points)
A. Nirvana
B. Dharma
C. Caste system
D. Buddhism

answer; eliminate parking problems in cities, because a car took up only half as much space as a horse and buggy;

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."