Answer:
Secondary research
Step-by-step explanation:
Secondary research involves using already existing data, like what can be found in in books, articles, and electronic databases.
A is wrong. Primary research is the research that you do to obtain new information, as in experiments or in interviews and surveys.
B is wrong. Qualitative research is the gathering of non-numerical data.
C is wrong. Summative research is done at the end of a project to determine its success. It can also point the way to future research projects.