Which of the following statements best summarizes the process of cultural sharing? a. cultures change over time as groups pass their values to other groups and adopt practices practices of other groups. b. culture is best defined as the values of a group of people, which do not change over time and are not shared with others. c. cultures only change by force, when one group imposes its values and ideas on others. d. cultural differences became indistinguishable by the beginning of the 21st century.