Under the Immigration Reform & Control Act $($IRCA$)$ employers are prohibited from knowingly hiring or retaining unauthorized aliens. Therefore for all newly hired employees, within $\_\_\_\_\_\_\_\_\_\_\_,$ the employer must verify employment eligibility by completing federal I$-9,$ which requires verification of their eligibility to work in United States.

Group of answer choices

first day of hire

$2$ days

$4$ days

$3$ days