Answer: B) Cross sectional study
Explanation:
Cross-sectional study is defined as the researching method through which population or other subject subset is observed and analyzed at certain period of time to evaluate their behavior.The data is gathered about different different population for assessment.
Other options are incorrect because longitudinal design, cross-lagged panel method or ex-post-facto researching technique is not used for measuring and analyzing the subject at a particular time stamp.Thus, the correct option is option(B).
