Homer creates a $3 million trust for the benefit of his three children. The trustee may pay so much or all of the income and principal of the trust to any one or more of Homer's three children as the trustee deems advisable. Any income not so paid is added to corpus. When Homer is no longer living the trust is to be distributed to the three children. Is it a gift in each independent scenario?

a. Homer is a trustee?

b. Homer is not the trustee but has the right to revoke the trust?

c. Same as b. but in each each year the trustee distributes $30,000 to each child?

d. Same as b. but Homer gives up the right to revoke in year 7 when the trust's value is $700,000.