A & B Are Married with Children C & D

A & B are married with children C & D, but were living separately from one another. A got married to E and begot children, F & G. After his death, E, F & G filed a petition for settlement of his estate. B, C &D intervened to claim their share of the estate and contended that since F & G are illegitimate as the marriage of A & E is void, their share is only ½ of the share of the legitimates. Is the contention correct?

A) The contention of B, C & D that the marriage of A & E is void is not correct because only A & E can question the validity of their marriage.
B) B, C & D can contest the validity of the marriage of A & E in the settlement of his estate as an exception to the rule due to the law on succession.
C) There is no use to question the marriage of A & E anymore because it has become moot and academic due to A's death.
D) The contention of B, C and D is not correct as they should have filed the settlement of estate of A and put up the defense of invalidity of the marriage of A and E if their children would intervene.