The correct answer is B. his patron, Frederick the Great, king of Prussia
Step-by-step explanation:
Johann Joachim Quantz was a famous flutist and composer during the 18th century. During his youth, Johann Joachim Quantz studied composition and different instruments but decided to focus on flute. It was then that he became one of the most relevant flutists in Europe and was hired by the Queen of Prussia. Besides this, when the new monarch Frederick the Great was elected in 1840 Johann Joachim Quartz continued working for the royalty and as part of this, he composed multiple flute concertos for the king. Thus, this flutist composed flute concertos for this patron, Frederick the Great, king of Prussia (Option B).