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[cb][bc]AB[ca][da][db][ac][ad][bd][cd]C[White to play - what's his best result?]PL[W]
(;W[dc]CR[dc]
;B[bb]CR[bb]
;W[ba]CR[ba]
;B[cc]CR[cc]
(;W[ab]CR[ab]
;B[aa]CR[aa]
;W[ca]CR[ca]
;B[ab]CR[ab]
;W[db]CR[db]C[Seki, White wins by one point (3 prisoners against 2) RIGHT])
(;W[ca]CR[ca]
;B[db]CR[db]C[Black wins])
(;W[db]CR[db]
;B[ca]CR[ca]C[Black wins]))
(;W[ba]CR[ba]
;B[dc]CR[dc]
;W[ab]CR[ab]C[Seki & jigo])
(;W[bb]CR[bb]
;B[dc]CR[dc]C[Black wins]))