Which of these traits are shared among almost all ethnic music ? 5-tone scale, universal theme ,use in religious ritual, vocal production.

I think the correct answer would be the third option. The trait that is common among almost all of the ethnic music would be that they are used in religious rituals. Almost all of these kind of music are made for rituals and offerings they are sung as offers to the gods. 

It depends on what type of third separates the three notes.for example: if you have two mayor thirds is an "aumented chord"if you have two minor thirds is an "diminued chord"if you have one mayor first and then one minor is a "mayor chord"and inverted is a "minor chord"