OE

A, E, G.

Orthodox (traditional) beliefs have caused various communities to expurgate or remove various practices from their midst. For the first blank, putative (supposed or reputed) does not fit the context. Some of these beliefs may have been occult ones, tied to the supernatural, but there is nothing in this sentence to support this choice. For the second blank, belie (show to be false) does not properly fit the sentence's grammar, while beleaguer (attack, usually in a military context) better fits people or places than practices. For the third blank, a community would remove practices that were antagonistic or hostile to their values. Endemic is the opposite and means belonging to a specific group of people, while something that is contentious causes arguments but is not necessarily damaging.