In $2019,$ Thalia purchased land for $$900,000$ and lists title in the names of her daughters as follows: $$April and Theresa, joint tenants with right of survivorship.$$ In $2021,$ April and Theresa purchase an apartment building for $$1$ million as equal tenants in common; April furnished $$400,000$ and Theresa furnished $$600,000$ of the cost. April died before Theresa in $2023$ when the land is worth $$1\mathrm{.}5$ million and the apartment building is worth $$2$ million. One of the results of these transactions is:

a$.$ April made a gift to Theresa of $$100,000$ in $2021.$

b$.$ None of the land is included in April$$s gross estate.

c$.$ April$$s gross estate includes $$800,000(40\%*$ $$2$ million$)$ as to the apartment building.

d$.$ April$$s gross estate includes $$1,750,000$ as to these properties.