def get_intersection_set(group):
    """ Task 2: gets intersection set of all questions in a group.
    Make a set for every declaration and return the intersection.

    :param group: list of strings
    """
    declarations = []
    for declaration in group:
        questions = set()
        for question in declaration:
            questions.add(question)
        declarations.append(questions)

    return declarations[0].intersection(*declarations)