(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[White]PB[Black]AW[gb][dc][ec][gc][mc][oc][pc][qc][gd][qd][ge][he][ie][pe][gf][if][pf][rf][hg][pg][rg][kl][ll][ml][nl][ol][ql][km][pm][kn][pn][bo][co][do][mo][no][po][ro][dp][op][cq][dq][eq][fq][oq][cr][gr][pr][rr]AB[hb][jb][cc][hc][rc][bd][cd][dd][ed][hd][id][pd][rd][fe][je][ff][jf][fg][jg][qg][gh][hh][ih][oh][ph][qh][rh][pk][qk][bl][pl][lm][mm][nm][om][bn][cn][dn][en][on][eo][oo][ep][fp][pp][qp][rp][gq][hq][br][dr][er][fr]LB[qb:2][rb:6][sb:1][qe:5][re:4][se:7][cf:D][nf:A][qf:3][el:B][mq:C]C[Helpful Comments - 

Problem A  looks impossible, but if you can find a move that threatens 2 things at once the problem is solved 
Problem B The obvious try fails due to shortage of liberties, once you discover this fact then the solution should not be too hard to find.
Problem C  Surprisingly difficult and easy to miss in a real game, black has only 3 liberties so you need to be fast - if no inspiration then there are only a limited number of possibilities to try 
Problem D is in my opinion both beautiful and difficult - here are a few hints 
1. is the eye in the centre unconditional ? 
2. The basic law of reduction first is the starting point. 
3. the proverb "there is death in the hane"  if you manage to solve the problem then reflect on what you have found  out, perhaps you will look upon  impossible life and death problems differently! 

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(;B[sb]
;W[qb]
;B[qf]
;W[re]
;B[qe]
;W[sd]
;B[se]
;W[sf]
;B[rb]
;W[ra]
;B[sh]
;W[sc]
;B[se]
;W[sd]
;B[sg])
(;B[bs]
;W[cs]
;B[bp]
;W[bq]
;B[ao])
(;B[qo]
;W[rn]
;B[qn]
;W[qm]
;B[sm])
(;B[cb]
;W[ea]
;B[ga]
(;W[fd]
;B[fb]
;W[fa]
;B[eb])
(;W[fa]
;B[fc]
(;W[fb]
;B[db])
(;W[fd]
;B[eb]))
(;W[db]
;B[fb]
;W[fa]
;B[gg]
;W[ig]
;B[fc])))
