In 1988, Triton and Ariel (father and daughter) purchased real estate for $500,000, listing the title as Triton and Ariel, joint tenants with right of survivorship. Of the purchase price, Triton furnished $400,000 and Ariel furnished $100,000. If Triton dies first in the current year when the property is worth $1,000,000, his gross estate must include:

Group of answer choices

$0

$500,000

$600,000

$800,000