Neuroimaging studies examining potential causes of schizophrenia have discovered that an area of the brain called the appears to have significantly less myelin coating on the axons of its neurons in people with schizophrenia compared to those without the condition.

answer; i believe that the correct answer is (tabula rasa);

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."

answer; english speaking;