Which of the following is true about DNA A. Chromosomes are found in DNA
B. DNA is found in the mitochondria
C. the nucleus is found in the DNA
D. DNA can be found in chromosomes

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."