What is the purpose of the preamble

The idea of liberalism in eighteenth-century british politics: a. had mainly a civic and social quality. b. prompted two eighteenth-century leaders, joseph mccarthy and hugh mccarran, to demand independence for ireland. c. brought great wealth and power to its main voice, john locke. d. was compatible with inequalities in wealth and well-being. e. had the same meaning as liberalism in twenty-first-century american politics.