Teresa: If their goal is to maximize profits, film studios should concentrate on producing bigbudget films rather than small-budget ones. For, unlike big-budget films, small-budget films never attract mass audiences. While small-budget films are less expensive to produce and, hence, involve less risk of unprofitability than big-budget films, low production costs do not guarantee the highest possible profits. Which one of the following is an assumption required by Teresa's argument? ['A film studio will not maximize its profits unless at least some of its films attract mass audiences.', "A film studio's primary goal should be to maximize profits.", 'It is impossible to produce a big-budget film in a financially efficient manner.', 'Each big-budget film is guaranteed to attract a mass audience.']