One of the primary differences between an $$old$$ pre$-2020$ Form W$-4$ and a $$new$$ post$-2019$ Form W$-4$ is:

a$.$ The new form does not account for the possibility of child tax credits in determining the proper withholding.

b$.$ The new form does not require any additional work if the taxpayer has two jobs.

c$.$ The new form requires the taxpayer to sign the Form W$-4.$

d$.$ The new form does not rely on the number of allowances to determine withholding