Congress passes a law that employers can give employees up to $12$ weeks unpaid leave to attend to family matters. The Virginia legislature decides that this in not enough and passes a law that that, in addition to the federal law, requires employers in Virginia to provide $16$ weeks unpaid leave. This law is likely:

unconstitutional because its terms are different from those of the federal law

unconstitutional because employee relations are a strictly federal area of concern

constitutional as long as the law does not unnecessarily impede interstate commerce because it strengthens the federal law

constitutional because states may regulate businesses in their borders in whatever manner they think appropriate

unconstitutional because it invades the police power of the federal government