question on an avalanche variation

[izabera]

this move was played by kobayashi koichi

$$c
$$ -------
$$ | . . . . . . .
$$ | . . O . . . .
$$ | . . O X X b .
$$ | . X X O O X .
$$ | . X O . . # .
$$ | . d . O a . .
$$ | . . . c . . .

Click Here To Show Diagram Code

[go]$$c
$$ -------
$$ | . . . . . . .
$$ | . . O . . . .
$$ | . . O X X b .
$$ | . X X O O X .
$$ | . X O . . # .
$$ | . d . O a . .
$$ | . . . c . . .[/go]

i looked it up on kogo's joseki dictionary and they recommend A B or C as moves for white, clarifying that D is a game-over mistake because of the throw-in at D15
why is this not the case for B?

edit:
it even goes on to suggest this continuation

$$Wc
$$ -------
$$ | . . . . . . .
$$ | . . O 4 . 2 .
$$ | . . O X X 1 3
$$ | . X X O O X .
$$ | . X O . . X .
$$ | . . . O . . .
$$ | . . . . . . .

Click Here To Show Diagram Code

[go]$$Wc
$$ -------
$$ | . . . . . . .
$$ | . . O 4 . 2 .
$$ | . . O X X 1 3
$$ | . X X O O X .
$$ | . X O . . X .
$$ | . . . O . . .
$$ | . . . . . . .[/go]

i don't understand why black would ever play instead of D15

[Uberdude]

It is. Kogo's has mistakes. Josekipedia.com is better (but not perfect).

[salerno]

Yes, White has to defend.

According to Takao Shinji's dictionary, this is the equal for both variation: