The single difference between Longitudinal and cross-sectional researches is Options: A) In Longitudinal researches are working on single group of subject for long term duration while in cross-section, the immediate results have been derived after selecting a sample B) In Longitudinal researcher the researcher should have more patience to work than in cross-sectional researches C) The Longitudinal researches have been generally carried out under the specific situation and with specific persons but it is not carried out in crosssectional researches D) All the above differences are correct