Using the property she inherited, Lily makes a $2023$ gift of $$16,920,000$ to her adult daughter, Sarah. Neither Lily nor her spouse, Greg, had made any prior taxable gifts. Assuming that a flat $40\%$ tax rate applies $($i$.$e$.,$ ignore the graduated rate structure$),$ determine the Federal gift tax liability if:

a$.$ The election to split gifts is not made.

b$.$ The election to split gifts is made.

c$.$ What is the tax savings from making the election?