Alexis wants to research the 1960’s feminist movement. She reads articles from the time…

Alexis wants to research the 1960’s feminist movement. She reads articles from the time period, watches documentaries, and reads scholarly journals on the topic; i.e. she takes previously collected data and analyses it in new ways. What kind of research method is Alexis using?
a. Ethnography
b. Surveys
c. Experiments
d. Secondary data analysis