Which of the Following Conduct Would Be Likely to Invalidate

Which of the following conduct would be likely to invalidate a will?

A) Maria urges her husband to leave all of his property to her.
B) Leah, who was not a blood relative, took care of Austin in his last illness.While he was in a weakened condition, she urged him to name her sole beneficiary to the exclusion of his children, which he did.
C) Paul does not mention his oldest child in his will.
D) All of these.