In January 2005, the only gratuitous transfer David made was to his son, Sonny. David gave Sonny a diamond watch. At the time of the transfer, the fair market value of the diamond watch was $5,000. Sonny immediately sold the diamond watch for $5,000. Sonny used the proceeds from the sale of the watch to co-purchase a boat with David, who also contributed $5,000 cash. They held the boat as joint tenants with rights of survivorship. In January 2009, David died. As a result of David's death, Sonny became the outright owner of the boat, which was valued at $8,000 on the date of David's death. Will any amount be includable in David's gross estate as a result of these transactions?

A. No inclusion 

B. $4,000 

C. $5,000 

D. $8,000 

E. $10,000