Answer:
c. Epidemiology on Covid 19
Step-by-step explanation:
"Epidemiology" is an idea, as it is a branch of medicine that deals with the study of patterns, causes, and effects of health and disease conditions in populations. "Covid 19" is a specific disease, but "epidemiology" is an abstract concept that refers to the study and analysis of the disease's spread and impact.
a. "Specific people" is not an abstract noun. It refers to concrete individuals.
b. "Chosen universities" is not an abstract noun. It refers to specific universities that have been selected or picked.