Which of the Following Spendthrift Clauses Is Enforceable

Which of the following spendthrift clauses is enforceable?

A) A settlor uses a spendthrift clause in a trust that lists him as the beneficiary.
B) A settlor uses a spendthrift clause to prevent his grandson from foolishly spending his assets.
C) A spendthrift clause that protects the beneficiary from creditors who have furnished necessaries.
D) A spendthrift clause that protects the beneficiary from being subject to paying child support payments.