Sentence Correction

In the English-Speaking world Anton Chekhov is by far better known for his plays than for his short stories, but it was during his lifetime that Chekhov's stories made him popular while his plays were given a more ambivalent reception, even by his fellow writers.

A)by far better known for his plays than for his short stories, but it was during his lifetime that
B)by far better known for his plays than he was for his short stories, but during his lifetime
C)Known far better for his plays than he was for his short stories, but during his lifetime
D)far better known for his plays than were his short stories, but it was during his lifetime that
E)far better known for his plays than for his short stories, but during his lifetime

my doubt:: i want to understand the usage of "by far". what makes option A so wrong? i got these following sentences regarding he usage of "by far" . kindly tell me if these constructions are rightly marked as "right" or "wrong"

Peter is by far more intelligent than his friends." ------>WRONG
"Peter is far more intelligent than his friends." ------> CORRECT
"Peter is more intelligent than his friends by far." ----->CORRECT