Zariah wants to know how kids of different ages think about smoking today whereas Estelle wants to know how attitudes regarding smoking change over time. The will best suit Zariah’s research question whereas the will be better suited for Estelle’s research.

cross-sectional design; longitudinal design

Explanation:

Cross-sectional design: In psychological research, the term "cross-sectional design" is described as one of the different study designs that are considered as an observational study. In this study, a researcher measures the "exposure" and the "outcome" in the study subjects or participants simultaneously.

Longitudinal design: In psychological research, the term "longitudinal design" is described as a study of participant or group of participants in a similar condition and over a period in time. It can last from a week to months and even to years.  

answer; i do believe that the answer is (c) electrolyte imbalance or (d) cessation of menstrual cycle; plz check first good luck

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."