While most surviving music during the Middle Ages is monophonic, the polyphony of the era is characterized by

the answer is letter b. false. fugue is a complex musical composition that does not occur or come together at the same time. in fact, it is composed of a number of voices or parts where the theme is introduced in one part and successively imitated in other parts.

relief sculpture - images are set against a flat background.

a coin is a good example: the inscription, the date, and the figure are slightly raised above a flat surface. the ancient egyptians sometimes carved figures into a flat surface.  

pro: they take significantly less time to make and do not require as much tools or skills as free-standing

cons: not nearly as realistic, as it is not fully 3-d, and does not have the details that a free-standing one does.

freestanding sculptures (also called  carved in the round) are not attached to any  background.   they are 3-dimensional  and fully rendered.