Cache fusion

How cache fusion work in 4 node RAC if all are doing update on same block  and in between any one of NODE get crash?

for example --

 A, B,C and D are nodes

5567 is the block number consist of 5 deferent rows

for example -

row1

row2

row3

row4

row4

row1 updated by A

row2 updated by B

row3 upadate by C

row2 updated by D.

So We have 3 cases --

1) what happen if B and D commit and A and C rollback at same movement.

2) what happen at A,B,C and D commit ?

3) what happend if node C creash other node commited or rollback.