Studies are based on observations that take place at a single point in time; these studies focus on behavior or responses at a specific moment.

Cross-sectional  

Explanation:

Cross-sectional studies: The cross-sectional studies are defined as the involvement of various groups of people who shares few characteristics but differ in the variable of interest in the study. It can be used in developmental psychology.

For example: educational background, socioeconomic status, religion, ethnicity, etc.

The cross-sectional studies are cost-effective and time-saving. it takes relatively lesser time as compared to the longitudinal studies.

answer; ///(c) i believe that the correct answer is ethnic relations bear many similarities across different global; good luck