Indian mathematics was able to make great advances in the 3rd and 2nd century BCE, in part because of their development of..?

The correct answer to this open question to this open question is the following.

Although there are no options for this question we can say the following.

Indian mathematics was able to make great advances in the 3rd and 2nd century BCE, in part because of their development of the decimal system and the invention of "zero."

Indians were smart people and great mathematicians. Great Indian mathematicians such as Brahmagupta or Aryabhata, also developed concepts on algebra negative numbers, and trigonometry that are applicable in modern-day mathematics. From India, these concepts spread to other far regions such as the Middle East or China, where other mathematicians and scholars improved these concepts.

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."