Could an executive be given prison time for refusing to testify about what he knew about criminal activity that he was involved in at the company's facilitles?

Yes He could be punished because refusing to testify is illegal:

Yes. An officer is always liable for crimes committed by a carnoration.

No$,$ he cannot be punished for refusing to testify if his testimony coula lead to covil charges against him.

Ns$,$ under the Fifth Amendment privilege againat self$-$incrimination.