Final answer:
The subject of this question is Social Studies, and it is asking about the age at which applicants receive a red color bar indicating the date they reach a certain age.
Step-by-step explanation:
The subject of this question is Social Studies, which focuses on the study of human society and social relationships. In this case, the question is asking about the age at which applicants receive a red color bar indicating the date they reach a certain age. This question is likely related to a specific social or cultural practice or policy.