Decisions in the performance of chamber music are made by

Decisions in the performance of chamber music are made by ALL THE MEMBERS OF THE ENSEMBLE.
Chamber music refer to the type of instrumental ensemble music which normally requires only one player for each part of the music. The most important chamber ensemble music that was known during the classical period was the string quartet, which is made up of two violins, one viola and one cello, making four in all.

Chamber music is composed by 2-9 people and they nod there heads to communicate during a performance. A septet is chamber music with 7 musicians. The decisions are made by the musicians because they can communicate among themselves.

So your answer is B!

King's portrait plays a significant role in his reign. Portraits helped in expressing his emotions (serious), to display his importance and power to his people in the kingdom. King's portraits assisted in showing off his wealth by indicating his surrounding and clothing in the painting. Portraits also served in showing his commanding presence and superiority.