I _____ the possible bad result. Right now, there is nothing I can do but take the full responsibilities.
(A)
had considered
(B) should consider
(C) should to consider
(D) should have considered

.......................

I _____ the possible bad result. Right now, there is nothing I can do but take the full responsibilities. 
(A) had considered 
(B) should consider 
(C) should to consider 
(D) should have considered ==應做而未做=>should have +PP，所以是 should(應該) have (要先如此)  considered(考慮)=>但沒這樣考慮

I _____ the possible bad result. Right now, there is nothing I can do but take the full responsibilities. 
我應該先考慮可能的壞的結果。==>但沒這樣做。

Right now(導致現在), there is nothing I can do but(除了) take the full responsibilities. =>這裡沒有事是我能做的事，除了付全責。