What is the purpose of using mass flowers in an arrangement?

Using mass flowers in an arrangement primarily serves to fill in spaces and create fullness. Mass flowers are typically larger, denser blooms that can occupy significant visual space, giving the arrangement a more abundant and lush appearance. This fullness is essential for achieving a balanced and harmonious look, as it helps to unify other elements like line and focal flowers. By effectively filling gaps and providing substance, mass flowers contribute to the overall aesthetic and ensure that the arrangement does not appear sparse or incomplete.

While mass flowers can indeed outline structures, create shapes, or serve as focal points in certain contexts, their primary function is to enhance the fullness of the arrangement, making option B the most accurate choice.