Beethoven was born in 1770.He studied first with his father.At 12he had some music published.In 1792he settled in Vienna.Around 1795his first important publications appeared.As a pianist，it was reported，he had fire，brilliance and fantasy as well as depth of feeling.These years also saw the composition of his first three piano concertos，his first two symphonies and a set of six string quartets.
1802，however，was a year of crisis for Beethoven，with his realization that the impaired hearing he had noticed for some time was incurable and sure to worsen.But he came through with his determination strengthened and entered a new creative phase，generally called his middle period.It is characterized by a heroic tone，evident in the Eroica Symphony，in Symphony No.5，and in his opera Fidelio.（18[A]）With his powerful middle-period works Beethoven was firmly established as the greatest composer of his time.
The years after 1812were relatively unproductive.（19[D]）He was seriously depressed，by his deafness and the resulting isolation and by the failure of his romantic relationships.But he came out of these trials to write hi s profoundest music，which surely reflects something of what he had been through.（20[C]）For Beethoven，the act of composition had always been a struggle；in the late works the sense of agonizing effort is a part of the music.

Beethoven established himself as the greatest composer（）.

A．with his powerful middle-period works
B．when his first three piano concertos were finished
C．around 1802
D．around 1795