Final answer:
The celebration involving crimson and palm green ribbons centered on Christ and service to others is specific to the Alpha Sigma Alpha sorority and is not one of the listed holidays like Christmas, Easter, Thanksgiving, or Independence Day.
Step-by-step explanation:
The national celebration described in the student's question, which involves wearing crimson and palm green ribbons and centers on Christ as an exemplar, is likely specific to the Alpha Sigma Alpha sorority. The celebration focuses on service to others and does not correspond with broader national holidays like Christmas, Easter, Thanksgiving, or Independence Day. Therefore, the national celebration they are referring to is not one of the choices provided in the question but rather a celebration unique to Alpha Sigma Alpha sorority.