Aresearcher decides to measure the concept of parental discipline by the use of spanking. this decision illustrates the process of:

explanation:

it was a suprise attack organized by geogre washington against the hessian forces in trenton, new jersey. it began the night o december 25, 1776 and ended december 26, 1776

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."