Homer and Laura were married. At the time of Homer's death, they owned the following: land as tenants by the entirety worth $$2,000,000($purchased by Homer$)$ and stock as equal tenants in common worth $$3,000,000($purchased by Laura$).$ Homer owned an insurance policy on his life $($maturity value of $$1,000,000)$ with Laura as the designated beneficiary. Homer's will passes all his property to Laura. How much marital deduction is allowed Homer's estate?

a$.$ $$4,500,000$

b$.$ $$2,500,000$

c$.$ $$3,500,000$

d$.$ $$2,000,000$