The church modes are:.
A. like the major and minor scales in that they consist of seven tones and an eighth tone that duplicates the first an octave higher.
B. different from the major and minor scales in that they consist of only six different tones.
C. completely different from any other form of scale.
D. different from the major and minor scales in that they consist of only five different tones.

A. like the major and minor scales in that they consist of seven tones and an eighth tone that duplicates the first an octave higher.

Explanation:

A. like the major and minor scales in that they consist of seven tones and an eighth tone that duplicates the first an octave higher.

Hi, the church modes are made of seven  tones and an octave like the minor and mayor scales.

All of the church modes were built from the notes in the C major scale. For example, the first mode was D, E, F, G, A, B, C, D (dorian ). The third mode began on E and used only the naturals: E, F, G, A, B, C, D, E (Phrygian). The fifth mode went from F to F (Lydian), and the seventh mode from G to G(mixolydian).

Feel free to ask for more if needed or if you did not understand something.

so easy. just google the electromagnetic waves and it’ll pop up.