Input (grade 13): G major and E minor both have a single sharp in their key signature at F; therefore, E minor is the relative minor of G major, and conversely G major is the relative major of E minor. The tonic of the relative minor is the sixth scale degree of the major scale, while the tonic of the relative major is the third degree of the minor scale.
Output (grade 6): C major is called the relative major of A minor.