Which of the following best describes the purpose of Form W$-4?$

a$.$ Report year$-$to$-$date compensation and withholding for all employees of an employer

b$.$ Report year$-$to$-$date compensation and withholding for a single employee

c$.$ Report the compensation of a non$-$employee worker

d$.$ Report the information necessary for an employer to withhold income tax from an employee$$s wages