This answer is true.
An ethnic group is a category of people that identify with each other based on similarities such as: common ancestry, language, history, society or culture.
Some ethnic groups can be ethno-religious, meaning that its members are also united by a common religion. Some examples of an ethno-religious groups are: the Jews, the Yazidis or the Amish.
An ethnic group can be composed of many religious groups. Some examples of such ethnic groups are the Kurds (both Shias and Sunni ) or the Mapuche people in Chile (catholic Mapuche as well as Animist Mapuche groups).
