Please find the best result for White!
(japanese rules)
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[4]KM[0.00]
PW[Weiß]PB[Schwarz]AW[bd]AB[da][cb]C[White to play - what's the best he can do?]PL[W]
(;W[bb]CR[bb]
(;B[cc]CR[cc]
;W[bc]CR[bc]
(;B[ba]CR[ba]
(;W[cd]CR[cd]
;B[dc]CR[dc]
;W[ab]CR[ab]
;B[ac]CR[ac]
(;W[ad]CR[ad]C[Seki, White wins by one point (the prisoner) RIGHT])
(;W[aa]CR[aa]
;B[ca]CR[ca]
;W[ad]CR[ad]C[Seki, White wins by one point (the prisoner) RIGHT])
(;W[dd]CR[dd]
;B[ca]CR[ca]
;W[ad]CR[ad]C[Seki, White wins by one point (the prisoner) RIGHT]))
(;W[ab]CR[ab]
;B[cd]CR[cd]C[Black wins!]))
(;B[cd]CR[cd]
;W[ba]CR[ba]
(;B[ca]CR[ca]
;W[dc]CR[dc]C[White lives, Black is dead.])
(;B[ac]CR[ac]
;W[dc]CR[dc]
;B[ab]CR[ab]
;W[ca]CR[ca]C[White wins])))
(;B[ba]CR[ba]
;W[cc]CR[cc]
;B[ab]CR[ab]
;W[bc]CR[bc]C[Black has no eye, so White wins]))
(;W[cc]CR[cc]
;B[bb]CR[bb]C[Black wins - b3 is a point that can not be missed])
(;W[bc]CR[bc]
;B[bb]CR[bb]C[Black wins - b3 is a point that can not be missed]))