Answer: Option (b) is correct option
Explanation:
According to the question,different countries persist varying opinion and beliefs on social identity of person in community as race trait according to their country's criteria. Thus, in Country A Sheila is considered black whereas Country B considers her white as per race criteria.
Other options are incorrect because of white and black saying of Sheila, gender of Sheila or ethnicity priority in a country are not main reasons due to which Sheila is recognized white and black in different countries. Thus, the correct option is option(b).