How Did Polyphony Change from the Beginning to the End

In terms of texture,High Renaissance composers: A) focused on the horizontal aspects of music at the expense of the vertical aspects. B) used polyphonic lines in such a way that a chordal quality was maintained. C) focused on the vertical aspects of music at the expense of the horizontal aspects. D) turned their attention away from polyphonic and chordal writing and focused on monophony.