5. Morphine functions as an:
A. endorphin agonist.
B. endorphin antagonist.
C. dopamine agonist.
D. dopamine antagonist.

The correct answer is letter B

It is called Ragtime a musical rhythm cultivated in the United States, especially between 1896 and 1917, is called ragtime, and it is recognized as one of the matrixes that formed North American jazz. Its origin is related to bars and juke-joints frequented by North American blacks, and its name derives from the expression "ragged time".

Strictly speaking, there are four main types of ragtime music, but the most well-known and still heard type today is the instrumental "classic" rag, which consists of a piece for piano or band, of syncopated rhythm, with a characteristic bass " boom-chick ". A typical example is the soundtrack to the movie "Stroke by Master" (The Sting), with Paul Newman and Robert Redford. In addition to this more well-known type, there are the "ragtime songs" or vocal rag, which eventually merged with popular music and the Vaudeville theater, the "ragtime waltzes" or "syncopated waltzes" (ragtime waltzes or syncopated waltzes), played in a 3/4 time, famous in the golden age of ragtime, and the last type, the "jazz rag", which consists of adapting any popular song and "breaking" or "tearing up" your time so as to leave it with a more danceable rhythm. Examples of this type of rag are found in "Mack the Knife" (originally the opening song for "Opera of the Three Vintems", a piece by the German Bertolt Brecht) and "Dinah", performed by several artists, including Louis Armstrong and Duke Ellington.