I would say the answer is B. Conflict led to its split into two separate kingdoms. Sorry if I am wrong, but otherwise I hope I was helpful for you.
1.melody short phrases, large leaps
Towards the end of the past century composers as Steve Reich La Monte Young, Philip Glass, they began to explore what is now called minimalism, in which the music is stripped down to its most fundamental features; the music often features repetition and iteration. An early example is Terry Riley's In C from 1964, perhaps a random work in which short phrases are chosen by the musicians from a set list and played an arbitrary number of times, while the note C is repeated in quavers behind them. Philip Glass works are on the most representative perhaps also featuring as soundtracks of movies.
2, harmony mixed meter
This caused a very new sensation with an extreme irregular rhytm. While time signatures usually express a regular pattern of beat stresses continuing through a piece (sometimes a section), sometimes composers place a different time signature at the beginning of each bar, resulting in music with an extremely irregular rhythmic feel.
Examples;Promenade -- Modest Mussorgsky's Pictures at an Exhibition (1874) The opening already shows signs of this implement
3· rhythm atonality
Atonality first began as a pejorative term to condemn music in which chords were organized seemingly with no apparent coherence. the term describes music that does not conform to the system of tonal hierarchies that were traditionally seen in classical European music between the 1700's and 1900'a centuries Example; ending Schoenberg's "George Lieder" Op. 15/1
4.dynamics extremes
some pieces started to use additional markings of further emphasis. Extreme dynamic markings introduced an extreme range of loudness, or, and sometimes accompanied with very small differences of loudness within a normal range, this huge change was made possible with the orchestration of the work, usually using many loud instruments like brass and percussion playing at once. It became more widespread in late 1900s.
Its A because George W. Bush signed this act into law in 2001.
