Q. 6 When is the National Anthem Song? What rules are to be followed while the National Anthem is singing?​

Since 1998, federal law states that during a rendition of the national anthem, when the flag is displayed, all present including those in uniform should stand at attention; non-military service individuals should face the flag with the right hand over the heart.

Hope this helps:)

i would say b. research typically uses a variety of sources