It was in 2012, when in Russian schools the subject 'Fundamentals of Religious Cultures and Secular Ethics' was introduced. Parents of students are given the opportunity to choose from six different modules. Among the modules there are 'Fundamentals of Orthodox Culture', 'Fundamentals of Islamic Culture', 'Fundamentals of Jewish Culture', 'Fundamentals of Buddhist Culture', 'Fundamentals of World Religious Cultures', 'Fundamentals of Secular Ethics'. However, the parents' choice is due to a variety of objective and subjective factors. The purpose of this paper is to elicit the degree of influence of four factors on the choice of modules within the course of 'Fundamentals of Religious Cultures and Secular Ethics.' To study the case, a polyethnic region of Russia -- the Republic of Bashkortostan, has been chosen. In this paper, the influence of four factors will be gradually revealed: the ethnic factor, the religious factor, the urban factor, and the factor of the educational environment. Studying the influence of factors determining the choice of modules demonstrates that the choice of modules is a compromise of many parties of interest: parents, students, teachers, clergy, and educational institutions.