Which of the Following Is True of Chekhov's Style

Which of the following is true of Chekhov's style?

A) Chekhov's eloquence comes in part through his use of dramatic understatement,as in Tusenbach's closing line before his death,"I didn't have any coffee this morning."
B) Chekhov never used irony,subtext,or understatement in his plays.
C) Chekhov never put monologues into any of his plays.
D) Chekhov used elaborate alliteration,as in the Commandant's statement,"I am the very model of a modern major general." and in general,used silly statements.