Which family preference category applies to unmarried sons and daughters of a USC?

The category that applies to unmarried sons and daughters of a U.S. citizen is the first family preference category, known as F1. This category is designated specifically for unmarried sons and daughters over the age of 21 of U.S. citizens, allowing them to immigrate based on their parent-child relationship.

In this context, it's crucial to recognize the difference between the family preference categories. The F2A category is for spouses and children of lawful permanent residents, while F3 is for married sons and daughters of U.S. citizens. The F4 category pertains to siblings of U.S. citizens. Each of these categories serves distinct family relationships and immigration qualifications, reinforcing why F1 is the correct choice for unmarried sons and daughters of U.S. citizens.