In each of the independent situations below, determine the Federal estate and gi

In each of the independent situations below, determine the Federal estate and gift tax consequences of what has occurred. (In all cases, assume that Gene and Mary are married and that Ashley is their daughter.)
a. Mary purchases an insurance policy on Gene’s life and designates Ashley as the beneficiary. Mary dies first, and under her will, the policy passes to Gene.
b. Gene purchases an insurance policy on Mary’s life and designates Ashley as the beneficiary. Ashley dies first one year later.
c. Assume the same facts as in part (b). Two years later, Mary dies. Because Gene has not designated a new beneficiary, the insurance proceeds are paid to him.
d. Gene purchases an insurance policy on his life and designates Mary as the beneficiary. Gene dies first, and the policy proceeds are paid to Mary.