Yes, you can absolutely rollover your 401k into a CD. However,
you will want to make sure that you roll it over into an IRA before
purchasing your CD to avoid tax consequences. If you do not do it
correctly, then you run the risk of being taxed at ordinary income
+ 10%. Beware!
eRollover is a great site that can help you to navigate a
rollover, as well as providing guidance for your retirement. See
attached link.