Problems declaring foreign keys, SQL Server

Question

I'm trying to create a table called Enrollments with two attributes that reference the foreign keys of another table. The schema for Enrollments is:

I'm trying to make SectionNo and Year of Enrollments reference SectionNo and Year of the CourseSections table (already created). Here is the schema for that relation:

Here is how I'm trying to add the foreign key constraints when I create the enrollments table:

I'm getting the error:

SQL71516 :: The referenced table '[dbo].[CourseSections]' contains no primary or candidate keys that match the referencing column list in the foreign key. If the referenced column is a computed column, it should be persisted.

Answer 1

Make SectionNo and Year as candidate keys.