An unmarried decedent has three children over 18 and four children under the age of 18. How many of the children need to agree on the funeral arrangement?

In situations involving funeral arrangements for a decedent who has children, West Virginia law generally requires that all of the adult children (those over the age of 18) must come to a consensus regarding the arrangements. Since this decedent has three children who are over 18, at least two of those adult children must agree on the funeral arrangements. This ensures that there is a collaborative decision-making process among the adult offspring, which reflects both the deceased's wishes and the family dynamics.

The presence of younger children does not play a role in the legal decision-making process in this context, as they are not of legal age to make such decisions. Therefore, the minimum number of adult children needed to agree on the arrangements is two, which aligns with the correct answer.